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Post by Darren Lim on Mar 10, 2004 2:12:59 GMT -5
Hi all,
I will use a 24"L X 12"W X 15"H case study here. Unfortunately (or fortunately?? ), since I'm Malaysian, I only know the RM prices of most items. This will take me a few days, so I will post them as I complete each one. Cheers.
Topics covered :
1) Tank & initial setup
2) Filtration & Water Tests
3) Lighting
4) Temperature
5) Livestock
6) Maintenance
1) Tank - get a size you can afford in terms of space and $$$. The larger the tank, the more stable the water parameters will be. Eg.1, if a damsel dies in a stable 6' 900 litre tank, nothing will probably happen in that tank. If the same fish died in a 1.5' 20 litre tank, it might wipe out everything!
Eg.2, - imagine a drop of bleach in the 2 tank sizes ...
Try to avoid getting a tank that is much taller than its width and length. This is to maximise the amount of oxygen that can enter via the water surface. Generally we recommend that the height be no more than the narrowest side. In this case, if its just 3-4" taller than its narrowest side, it's ok, since we use the extra height for the sand bed (covered later).
Eg.1 For a 24"L X 12"W, tank, you can go up to 15"H. When the sand goes in later to a height of 3", you willl end up with a max. water height of 12". If you must have a super tall tank, keep the fish load lower as in a standard height tank.
Eg.2 If you have a 5'L X 2'W X 2.5'H tank, treat it as if it were a 5' X 2' X 2' in terms of fishload and you'll be ok.
Normally, for SAFE bioload levels, we'll put no more than 1 inch of fish for every 5 US gallons of SW. This means that in my case study tank of about 15 USG (less sand, air space and rock space), I'd have no more than 3" of fish.
Most tanks in the market are longer than they are wide. But nothing's stopping you from having a square tank. In fact, the increased width gives you fantastic depth, and you can FOUR diff. views of the same tank. Aquascaping opportunities are almost unlimited.
Whether to have IOS, overflow system or not : In a marine tank, organic wastes float mostly at the surface, so they need to be removed some way or other. Otherwise they will reduce oxygen from entering the water, and light from penetrating the depth fully. Whichever method you use, water has to flow from the tank surface into the overflow compartment, and not from the bottom. It is also possible to achieve this by using a surface skimmer device, although the flowrate will be lower.
Remember that if you use a regular overflow compartment, you will also need a sump tank and do some piping, which is extra costs. Oh, and if you already have a tank but you need to drill an overflow hole, most shops will NOT do it for you, unless YOU bear the risk of the tank cracking. In cases like this, it is safer to modify your tank for an IOS, or use a surface skimmer.
Case study :
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A 2' tank is usually too small for an overflow compartment, and the sump will be even smaller. However, if you MUST have a sump, an alternative which won't take up too much space would be to have a 1.5" overflow hole drilled into the back pane of the glass. This hole should be be about 2" down from the top, and placed at least 2" from either side of the tank. Then you can fix a PVC tank connector and a PVC elbow to this hole. Position the elbow so that the opening is pointing up, perfectly horizontal. This will be your overflow opening. One thing to note. With a sump tank, you'll need a reasonably large pump to draw water back up into the tank (you do NOT need and must not use a pump to push water through the overflow hole - gravity will do the job for you). These pumps generate quite a bit of heat in the tank, so you'll need additional cooling.
It would be more feasible to have an IOS built into the tank. You can get a shop to do it for you, but just request for a surface overflow. It only has to be big enough to hold your protein skimmer, and its pump (if you're using a powerhead-driven type) or just the skimmer (if it's an air-driven type).
My preference would be to skip all these drilling and gluing, and to just use a surface skimmer. You can get the Aquaclear model very cheaply nowadays - should be less than RM30.
An even cheaper alternative - forget everything, and once a week, just skim off the surface manually using a bathroom scoop (without the soap!). By the time you get it all, you might have removed as much as 10% of the water, so you can treat this as a water change at the same time
Cover or no cover? Covers are very useful for mounting lights and fans and for hiding equipment that stick up, like the protein skimmer collection cup. But, they reduce air flow. This can be solved by making sure there're lots of holes at the back of the cover, and if possible at the top as well, since warm air rises. Wooden covers are better to work with, since they can be drilled and screwed properly. Plastic isn't very good for this.
Initial setup:
Get a hydrometer - floating type, or swing-arm - doesn't really matter, most of them aren't very accurate anyway! This will cost between RM6-40. If they're off by a small amount, it's generally ok. If your LFS has a refractometer, you can ask him to calibrate it for you, but be prepared to pay for the service.
Get 2 kg of decent marine salt like Instant Ocean or Sera Premium costing about RM15-20
Get about 17-18kg of #0 or #1 crushed coral or beach sand or even crushed white marble-about RM50 (related to topic 2)) - this will be enough for about 3" thickness.
Get a powerhead rated at about 600lph for circulation - this is fine just for slow-movers like Nemos (Ocellaris clown), and corals that don't like high water flow, like most LPS hard corals, e.g., anchors, hammers, elegance, etc. An alternative would be to use double smaller powerheads so you can have some turbulence when the water flow crosses each other. Also, you'll have some backup here, just in case one of the powerheads dies on you. However, having 2 smaller powerheads might warm up the water more than 1 larger unit.
Pour the sand into the tank, and level it out - does not have to be perfect, since the powerhead will re-shape it for you anyway, and place a plate on top of the sand.
Use a pail (no soap or anything else), and depending on the size just fill it with water - preferably RO or RO/DI. NSW (natural SW) in South-East Asia contains about 1kg of salt for every 30 litres of water, or about 33 ppt. So if your pail is 20 litres, put about 650g of the salt into the pail of water and mix it up. It's ok if it's slightly on the tasteless side or salty side, since you can always adjust it later. You may have to wait and stir a while before the salt dissolves fully. Use the hydrometer to ensure that the salinity is about 33ppt or 1.024 SG. If you're using the swing arm type in a plastic box, tap on the box to make sure there're no air bubbles sticking to the arm. When you've got the correct salinity, pour the SW gently into the tank ON TOP of the plate. Repeat this until you have enough water to reach about 2 - 2.5" from the top of the tank. Then remove the plate.
Attach the powerhead(s), and turn them on, letting them mix the new SW really well.
Note on SG/SW density. Many LFS set the salinity of their holding tanks to about 1.020 or even as low as 1.018. There are reasons for this, and it's not just to save the cost of salt. At lowered salinities,
a) More oxygen stays dissolved in the water.
b) External parasites like white spot, velvet usually cannot survive for long. In fact, hyposalinity to as low as 1.010 is sometimes used to treat white spot.
c) pH is slightly lower, so NH3 becomes less of a problem.
Disadvantages:
a) Fish colours will fade
b) Corals don't do as well in the lowered mineral levels
c) Even though NH3 is not so dangerous, NO2- becomes more dangerous.
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Post by Darren Lim on Mar 10, 2004 2:13:42 GMT -5
Filtration
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Of the 3 types of filtration, i.e., mechanical(physical), biological and chemical, biological is by far the most important filter to have in the tank.
Mechanical - use of media like sponges, to filter off solid particles like solid waste, uneaten food, detritus.
Biological - use of beneficial bacteria to break down products in the nitrogen cycle like NH3, NO2-, NO3-.
Chemical - use of chemical resins and carbon to absorb specific ions like NO3-, PO4-, colours, smells, etc. A protein skimmer usually falls into this category even though it's using air as a basis of enabling organic particles to stick to the foam.
Over the past decades, many filters have been designed for FW and SW tanks, using a wide variety of media. There are the undergravel filters (UGF), box or corner filters, hang-on-back (HOB) filters, canister filters like the Eheim, internal filters attached to the bottom of a powerhead, internal filters that are complete units with mech., bio. & chem. sections, overhead filters, fluidised bed filters, UV-filters, and numerous others. There is more than one way to skin a cat, which implies that no one filter is perfect for everything. However, certain filters like the UGF are generally not acceptable in marine tanks because of detritus build-up in the gravel/crushed coral bed and clogging of the filter plates. You'll just have to keep telling yourself time and time again : "Think Biological, BUT think carefully".
Bio-filtration relies on the use of various types of beneficial bacteria in order to process/breakdown/assimilate/mineralise organic wastes to ammonia NH3 (toxic), to nitrites NO2- (toxic), to nitrates NO3- (non-toxic in low concentrations, very problematic in high conc.), and finally to nitrogen gas, N2 (totally inert and harmless). When you reach N2 in gaseous form that gets released into the water, your nitrogen cycle is complete. People sometimes talk about Nitrobacter, nitrosomonas, but the names are unimportant. Just remember that there are 2 main phases in the nitrogen cycle :
1) nitrification, handled by nitrifying bacteria in an aerobic (with oxygen) environment.
2) DEnitrification, handled by denitrifying bacteria in an anaerobic (no oxygen) environment.
The nitrification phase handles the "conversion" of NH3 to NO2- and NO2- to NO3-.
The 1st bacteria that does NH3 to NO2- multiply pretty quickly, usually within several hours, but may not completely convert the NH3 quick enough, depending on how high the level is. This of course depends on how soon you put in the fish after you set the tank up, and also how much you've been TRYING to feed the fish.
The 2nd bacteria that does NO2- to NO3- multiplies much slower than that, possibly taking as long as 2 weeks to have enough to handle the NO2- levels produced by bacteria 1. All filters with biological media will handle this part of the nitrogen cycle pretty well, with some being faster than others. The highest speed ones seem to be the trickle filters and the fluidised bed filters. However, the faster NO2- is broken down, the faster NO3- is produced!! So sometimes this may not be too desirable. This method is only good if you need to set up a tank in a hurry, say for an exhibition, and you don't mind changing the water after the show. Or relocating the fish to a safer and stabler environment after that. It is in cases like this that aquarists will jump-start the nitrogen cycle by using things like BioZyme, Cycle, etc.
The denitrification phase is the slowest and usually the phase that cannot be achieved by most of the filters mentioned above. The reason for this is that in traditional filters, there's lots of water flowing thru' the filter media, and this water carries lots of oxygen ... if it didn't, your fishes and corals would probably already be dead Unfortunately, in the presence of oxygen, the denitrif. bacteria cannot survive, and thus the NO3- that are produced by the regular filter media cannot be converted to N2 gas, and this NO3- level will climb higher and higher until it's well beyond control.
Problems with Nitrates : Fish can do well at levels of up to about 40ppm NO3- easily, and I've seen some tanks with NO3- levels at 400 ppm!!! At these elevated levels, fish growth will have stopped, they have internal problems, and your tank will most likely be totally covered with a disgusting layer of red slime algae, commonly known as cyanobacteria. No fish eats this type of algae. Period! It's quite easy to siphon out the algae, since it's very light and doesn't stick hard to the surfaces. However, even if you siphon out everything today, in 2 - 3 days, it will be back even faster than before. There is no other way to go about solving this problem other than tearing down the tank and resetting it up then. Not gonna be fun
This is the reason why people like Schott invented Siporax, a filter media using something called sintered glass (haven't figured out what it is yet!!), which is structurally diff. from crushed corals, bio-rings, etc. The inner portion of sintered glass has a lot of very fine micro-pores, which do not let much, if any water pass thru'. As a result, the denitrifying bacteria can live in here. Unfortunately, Siporax is VERY expensive, and still not as efficient as a deep sand bed, as will be detailed further down below.
The Berlin system and DSBs : Sometime in the early to mid- '90s, some people in the US realized that by using LR (live rock), a protein skimmer and nothing else, their NO3- levels could be kept very low, much lower than what was previously possible with any other filter, EVEN with Siporax, provided they used enough of it. They discovered that deep within the inner portion of a piece of LR lived lots of denitrif. bacteria since water doesn't really flow thru' it much. The protein skimmer exported most of the organic wastes BEFORE they became NH3, so it gave the bacteria colonies a headstart. For the amount of LR to use, normally we put in about 0.6 - 0.7kg per US gallon of water. In our case study tank of about 15 USG, I'd put between 9-11kg of LR, right on top of the sand bed that was made in Topic 1.
Towards the later part of the '90s, deep sand beds (DSB) started getting being used in reef tanks. And people then realized that 0 ppm NO3- was actually possible. This was because when you're using oolitic aragonite, or #0 crushed corals, or even silica sand, there were so many sand particles crammed next to each other that the surface area for bacterial colonisation was fantastic. Added to that was that the deeper you went in the sand bed, the less oxygen there was, so beyond the first 1.5" or so of the DSB, all the below portions were mostly anaerobic!!! Basically, a DSB is just that. Nothing more than lots of sand at the bottom of the tank, with nothing underneath it. Most DSB depths range from 2" to 6", depending on how tall your tank is, how much swim room you need for your fish, and how heavy a bio-load you anticipate to have in future.
For our case study tank, we can afford to have 3" of DSB, and still have about 11" of vertical swimming space, and 1" of air space left behind. Most fine sand or aragonite weigh in at between 32kg - 36kg per cu.ft., depending on the pore size. In order to calculate the weight of sand needed, you can do L(feet) X W(feet) X H(inches/12) X 35kg to get 17.5kg of #0 sand.
Tank cycling : For new setups in order to avoid sudden and unexplained deaths caused by New Tank Syndrome (NTS), the tank has to cycle. What this means is nothing more than giving it enough time for all 3 types of bacteria to multiply and colonise the sand bed, assuming that your LR is already colonised. Generally, this takes anything up to a month, and its success can be observed easily by examining the DSB after the 1st week or so. As time goes on, usually after the 1st 2 weeks, you'll notice more and more little "air" pockets forming in the DSB next to the glass. This is not air, but nitrogen gas which indicates that the denitrifying bacteria have already started multiplying. Remember to test your water for NH3, NO2- and NO3- on a weekly basis, which will let you know the status of your tank's stability - you CAN'T guess. After a month, NH3 and NO2- should both be zero. NO3- may or may not be - usually it'll be low, but not quite there yet. If it's less than say, 10ppm, you can go ahead and put in some easy corals, but don't put any fish in yet until the NO3- have actually reached zero. This will give the colonies a real headstart against what fish you add later. Better still to wait for it to have reached zero first.
Reason why you can't have as many fish in a marine tank as you can in a FW tank : Even when your tank has cycled, you should never overcrowd your tank for 2 reasons : 1) Overcrowding causes stress, which can then cause infections to start in your fish. 2) Higher pH levels than in FW means that most NH4+ (ammonium ions) are converted to NH3 gas which is many times more toxic than the ion found in FW tanks (unless you're talking about Malawi or Tang. tanks).
Other regular water tests to do : KH - helps to buffer pH (much more than crushed corals) and prevent it from swinging, as long as it's kept at 8 degrees or higher. Also contributes largely to formation of calcium carbonate in coralline algae and coral skeletons. Calcium - especially necessary if you plan to keep hard corals, but also good to know, in order for your coralline algae to grow quickly.
Final note : You can still use sponges, but not on a regular basis because they will filter off the plankton in your tank produced from the shrimps, crabs, worms, snails, etc., in the LR and DSB, which will deprive your corals of their natural food source. Carbon used long term will deplete your trace elements.
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Post by Darren Lim on Mar 10, 2004 2:14:34 GMT -5
Once in a while however, you may come across a situation where Berlin plus DSB may just not be good enough for the application. A typical case would be that of a predator tank. All meat eaters generate lots of waste, and NH3, NO2- and NO3-. It may be and usually is too much for these filters to handle.
What we normally do in this case is to use trickle filters coupled with denitrifiers, or skip the denitrifier and do more regular water changes of larger amounts.
You can still have the LR and protein skimmer and DSB, and this will help to a certain extent, but not on their own.
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Post by Darren Lim on Mar 10, 2004 2:15:12 GMT -5
Topic 3 - Lighting
In this topic, I will cover all the aspects of lighting, including but not limited to colour, intensity and duration.
Firstly, for fish, the amount, type and duration of lighting is not too crucial. Lighting basically makes the fish look more attractive, and most of them will be out swimming, looking for food.
For most of the corals that we keep however, lighting is a VERY important part of their lives. There are 2 major groups of corals, the photosynthetic and the non-photosynthetic groups. Lighting is important for the photosynthetic group only. The other group can do with, or without it.
In the photosynthetic group, corals usually come from areas of the ocean between 5 feet to about 60 feet or so. These could be a mixture of hard corals, soft corals, and even anemones which are a class of their own. Whichever type, all of them have in common a type of algae called symbiotic dinoflagellates, or zooxanthellae that live just under the coral surface. These zooxanthellae are brown in colour, and utilise the light, as well as CO2 in order to product sugars for the corals. It is this special type of "brown algae" that gives many light-loving corals their brown colours. This is why many NON-photosynthetic corals like the carnations (dendronepthya, scleronepthya, etc.) are so brilliantly coloured in pink, purple, orange, scarlet, etc., since they don't have these algal cells in their tissues.
Colour
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Colour is quite an important part to consider. In shallow waters, sunlight is quite complete. As you go deeper and deeper, you will lose red first, followed by orange, yellow, green, blue, and finally purple at super depths where everything is black. But at depths of even 60 feet, you will still have most of the colours except red and orange. Many people (especially LFS owners) will try to tell you that actinic blue (lights are critical for the success of photosynthetic corals. This is NOT true. Actinic blue or 03 lighting is a single frequency light that peaks at 420nm, and appears purple blue. Certain corals found deeper than 60 feet have learnt to utilise this frequency of light since they have no choice. However, none of the corals we buy come from these depths. They come from very shallow waters where they depend on and need full spectrum white light. The actinic blue tubes actually serve to enhance the colours of the corals (and fish).
Colour is measured in terms of colour temperature, denoted by the K (Kelvin) rating. Noon sunlight (above water) is about 5800K, which is slightly yellow. As the K rating goes down, the colour becomes more yellow, then orange, then red. This is why if you look at a household fluorescent tube like Philips 827 (2700K) tubes, the output is very yellow, the 840 (4000K) is less yellow, and the 865 (6500K) is very white with just very little yellow left. If you go up to 10000K, the lighting will be totally white, no yellow at all, at depending on the brand of light, you might even see a very little bit of blue. From 10,000K onwards, The higher the K rating, the bluer the light will appear. 12000K or 14000K are considered as white-blue, and look quite good. 20,000K bulbs are blue-white, and usually not white enough, unless you increase the power rating of the bulb used. 50,000K available nowadays are totally blue, and are only used to supplement 6500K daylight bulbs.
As far as corals are concerned, they do best and grow fastest under 6500K since this is full-spectrum. As far as humans are concerned however, this is too yellow for the human eye, so people either add a few actinic blue tubes to balance out the yellowness of the 6500K, or they use 10,000K or even 12,000K with or without additional actinic blue tubes.
High K-rating tubes have 4 disadvantages :
a) Lower intensity than daylight tubes, even at the same power consumption.
b) Very much higher cost
c) Very quick drop in colour from blue to white to yellow, as fast as 6 months (low colour retention)
d) Appear dimmer than daylight bulbs - because human eyes are not sensitive to blue, and usually the way the manufacturers make the K rating higher is to reduce the phosphors used to produce the other colours, so that more blue phosphors remain.
With these disadvantages, you might want to think twice before using 10000K, 12000K, 14000K or 20000K tubes. 10,000K isn't too bad, since it's still quite white, but within 9 months or so, it will started turning more and more yellow. The 6500K and 6000K tubes in the market, being at natural daylight colours do not suffer a colour degradation that fast, being able to
retain their colour for as long as 1.5 - 2 years
Duration
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Keep your lighting on for between 8 - 12 hours. Your corals need to rest as well, and so do your fish. Also, if you extend the period, you might start getting unwanted algae problems. You can use a timer to control this period. It does not have to coincide with our daylight hours. You can do say, On at 1pm, off at midnight for 11 hours. This way, after work/classes, you still get to enjoy the tank. If you suffer a power failure, some timers need to be reset unless they have a built-in battery supply or memory feature.
Intensity
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When we talk about intensity, generally we're not referring to Watts - this is a measurement of power consumption, and not output. An obvious example is a 40W incandescent light bulb compared to a 40W fluorescent (FL) tube. The tube is VERY much brighter. Similarly, a 36W PL-L 6500K tube is also much more intense than a 36W FL tube. The intensity of a bulb is directly related to the depth of water the light can penetrate. For instance, a 400W MH (metal halide) bulb puts out about the same intensity as 10 X 40W FL tubes. However, because MH light is a point-source light, ALL the intensity is concentrated at one point and this is why it can penetrate down to at least 30" easily, whereas 40W FLs only go down to about 12" effectively. Adding 10 FLs does NOT make any difference. You just get a much wider spread, but the penetration is still 12" per tube, just over a wider area only.
In the past, a favourite form of measurement used to be watts/US gallon, and ranged from 5-10 W/G of white light for reef tanks. Because reef tanks could be very odd-sized, some tall, some short, this wasn't very practical, and nowadays more people are starting to use W/sq.ft. of surface area, lying between 50 - 150W / sq.ft. of white light, depending on the corals you plan to keep.
Note on effective water penetration power of bulbs and tubes :
Fluorescents - down to 12"
CF like PL-L, T4 and T5 - to 15"
MH 70W to 16"
MH 150W to 20"
MH 250W to 24"
MH 400W to 30"
There are also 1000W and 2000W bulbs, but generally not for household tanks.
How intense for different types of corals : All soft corals (excluding mushrooms) do very well under medium to high intensity. Hard corals are usually divided into LPS (large-polyp scleractinians) or SPS (small-polyped scleractinians). LPS corals include brains, anchors, hammers, bubbles, torch, elegance, goniopora, alveopora, plates, galaxy, etc., i.e., those where the fleshy part is very obvious and quite large. SPS corals are those with very small polyps like Acropora, Montipora, Porites, etc. LPS corals (and mushrooms) do fine with low to medium intensity light. SPS do well only under high and very high intensity. BTW, anemones also prefer high to very high intensity, depending on the species.
CASE STUDY : For a soft corals, I'd want to target for at least 70W/sq.ft., so in my tank, I'll go for about 4 pieces of 36W daylight PL-L tubes, with 1 more 36W actinic blue PL-L tube for added colour. This will be 144W of white light, and 36W of actinic blue. Bear in mind that the PL-L tubes are about 1.5" wide each, so 5 of them will occupy at least 2/3 of the tank width already. You still need to use AC fans to cool the tank down, especially with these many lights.
For LPS corals and mushrooms, I could use 3 pieces of 36W white PL-Ls, and a single 36W actinic blue PL-L.
For SPS corals or anemones, I would just use a single 150W 10000K or even a 250W 20000K MH. The reason why I can use a 250W in such a shallow tank is because 20000K bulbs are very much dimmer than a 6500K anyway.
NOTE :
Whenever you're using high intensity lighting, you have to be careful not to "sunburn" your corals. This can happen very easily, if the LFS where you bought your corals from use only FLs (like me). If you subject these newly bought corals to intense MH light just a few inches above your coral, usually your coral will bleach. They may even die. This is because the coral will eject their zooxanthellae since there's suddenly a lighting overload and they don't need so much zooxanthellae anymore. But sometimes they may get carried away. This is the reason why LFS who do not know about lighting principles always say that you can't use MH, they'll kill your corals, etc., etc. They just haven't acclimatised the corals yet. What you should do is to place the new arrivals at the dimmest spot first, then week by week, move them slowly up to their final "resting place".
Just FYI, our tropical sun at noon is more than 3X brighter than a 400W MH bulb, so you can't say that the MH will kill your corals.
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Post by Darren Lim on Mar 10, 2004 2:16:10 GMT -5
Topic 4 - Temperature Control
In this topic, I will cover various ways of keeping the temp. in your tanks lower than normal.
Generally, for FO (fish-only) or FOWLR (fish-only with live rock), it is not really necessary to cool the water. Having said that, fish will generally also do better with slightly cooler water. At higher temp., their metabolic rates are higher, they eat and pass waste more. They will also be less active as would we humans be at higher temp. If you can keep the temp. for fish down to 30C or slightly less, this will be fine for them.
For corals and some other inverts, they have a much narrower temp. tolerance range, usually between 22C to 30C. At these 2 limits, they will not really "die", but they'll be closed most of the time, and over a longer period, will not survive, especially if they're the photosynthetic type where they need to open up to capture the light.
In most cases, we try to achieve a temp. range of 26C to 29C for corals to do really well. At these temp., fish will do equally well, so it's the best of both worlds.
Methods of cooling :
1) Chiller using compressors with :
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a) externally cooled canisters - these are average in price, usually about RM1200-1500, for anything from a 2' tank to a 4' tank. They work on the principle of a copper coil wrapped around a small canister filter, and having the whole thing insulated with thick rubber. Water enters the canister and is pumped back to the tank by means of a pump in the canister head. These are all commercial units made by aquarium eq. manufacturers.
Disadvantage : Very limited and inefficient cooling, since the coil cools the plastic casing of the canister, and this then only cools the water. For anything bigger than 4', this will be difficult.
b) stainless steel (SS316 preferable)/copper coil immersed in a small sealed glass tank of FW that sits in the sump. Slightly better than 1a), but cooling effect is also reduced by layer of glass between FW and SW. However, it can cool larger tanks by simply using a larger coil and a larger compressor. However, your power consumption bills will be higher than "real" chillers in 1c). About the same price as 1a), since it's mostly DIY - you can get aircon people to bend the SS coil for you - might cost about RM200-300. Then you'll need a compressor - aircon or fridge type, ranging in price from RM600-900 depending on brand. Then you'll need a sensor that dips into the FW tank and a digital controller (RM200) that uses the sensor to turn the compressor on and off. Lastly you'll need an AC guy to connect up the whole thing for you - about RM150-200. Since the sensor is in the FW, if it reads 26C, it could actually be 27C in the SW. Some people insert the sensor into a small thin plastic bottle, fill it with FW, seal the whole thing and drop it into the SW section instead. In this case, if the reading in the little bottle is 26C, the actual SW temp. could be 25-25.5C
c) Titanium coil immersed in sump of SW. Everything else is the same as for 1b) but you don't need the FW tank. Price for 1/2 hp unit about RM600-650. Coupled to a 1HP compressor, can cool up to 1,800 litres. Larger coils will cost more.
d) Titanium coil sealed inside a drum - called a heat exchanger. In this case, the drum has a water inlet, a water outlet, and a sealed small hole for the sensor to be inserted into. A pump in the sump will push water into the drum inlet, and the cooled water will flow back into the sump from the outlet. The sensor is inserted directly into the sensor hole, which is also titanium, so it sensors the water temp. directly. Priced from RM770 to RM2000 depending on the drum and coil size.
2) Evaporative cooling using fans:
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This can be quite efficient for smaller tanks, and work on the physical principle that when water evaporates, it cools. For small tanks, we can use 4" - 5" AC fans. Forget those commercial aq. fans with 4 or 5 small 2" fans in a row, running off a DC power supply. They don't have the power to do the job, and cost even more. For larger tanks like 3', 4' or even more, you can also use exhaust fans like those 10" or 12" units mounted over the tank or over the sump. Using fans to cool a tank is a lot cheaper than using a chiller, but there are 3 disadvantages :
a) Temp. fluctuation can be quite high, since it drops the temp. 2C or at most 3C depending on the surrounding temp. and humidity. This kind of fluctuation on a daily basis could cause stress in some corals. To prevent this from happening, you can still use a sensor and digital controller as mentioned in 1b), to control the fan(s).
b) If you have any SW sprays or bubbles in the tank, these could coat the fans and i) shorten the life of the fan and/or ii) cause a power-leakage - very dangerous. Just avoid any air pumps in the tank, do not cause water to splash at he surface (another reason to avoid Overhead filters).
c) Evaporation rates will be super high. But it has to, since the faster and the more it evaporates, the more it cools. If you're using an enclosed tank without an overflow system, just use a permanent marker pen to mark the standard water level. When the water drops below this level, top up using FW or RO water or distilled water, NEVER salthingyer, as salt does not evaporate. If you're using a tank with an overflow system, mark the level in the sump, since the tank level will remain constant.
3) Peltier cooling :
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This use a technology developed for PCs using a cooling fan, a huge aluminium heatsink and a Peltier junction to draw heat away. There is a commercial one in our hobby called the IceProbe retailing in the US for about USD100, but it's good for only up to a 15G tank (2' X 1' X 1'). It comes with some sort of ceramic rod that's immersed in the water and cools it. The rest of the device is above water. Some people install them into Hang-On-Back filters by drilling a hold in the cover and inserting the rod inside.
Handling Evaporation
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Instead of topping up with just water, you can also top up with a frozen bottle of ice, but without the cap on. This will help to lower the temp. even more. Just make sure the iced bottle doesn't touch any coral.
If topping up daily seems tedious, you can also build a top-up system. There are float switches and sensors in the market but these are usually quite expensive - RM150-200, that control a pump in a bucket of FW to topup the water for you.
You can also use a slow drip method to do the topup for you. Just place a container(s) that can hold more water than your daily topup volume somewhere above your tank/sump. Connect an airline tubing and airline valve and insert one end into the container right at the bottom. Start the siphon, and tighten the valve until the drip is slow. It is all trial and error to figure out how fast the drip should be, but you can experiment in your basin first.
Another topup device you can use would be a simple ball float like in the toilet cistern. This is usually used in tanks with sumps, so you can't see the ball !! You'll have to do some piping either from the water mains or from the same container as in the slow drip method. If you use mains water to topup, make sure you either connect a filter in the middle with a carbon cartridge to remove the chlorine. Or when water enters the sump, it MUST by pass an activated carbon section first.
Advantage of 2c) When evaporation rates are high, you can take advantage of this by topping up with KW (kalkwasser) or a saturated solution of calcium hydroxide, Ca(OH)2 (quite cheap - about RM60/kg, will last for ages), instead of just FW. What KW does is 3 things :
a) Maintains the calcium level for you. However, if your Ca level has dropped too much, it can't push it up for you.
b) Maintains the KH for you, which in turn prevents your pH from fluctuating.
c) Precipitates phosphates (PO4-) for you, which reduces green hair algae growth.
For KW to be used, you'll have to use the slow drip method, because saturated KW has a pH of about 12.4, and pouring it straight into your tank will wipe it out. When you use KW, you can mix about 1 teasthingy in 1 litre of FW, shake it up properly until you still see some residue left behind. This means that the solution is saturated. Wait for the solution to clear first before you use it. KW is very unstable, and will react easily with CO2 in the air, so for the topup drip container, you must have a cover with a hole drilled in it for the airline tube to pass through. You will need a 2nd hole in the same cover, to allow air to be sucked in when the drip starts. Otherwise if the bottle is airtight, the KW will not flow. Also, make sure the bottom of the airline tube in the container is about 1" above the bottom, to prevent the residual Ca(OH)2 from being sucked into the tank.
Case Study :
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For our 2' tank, I would use 2 X 4.5" AC fans mounted on the hood, spaced about 12" apart, more towards the back, (since the lights would be in front), pointing downwards. Then I'd assemble a topup container for KW additions using a drip valve.
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Post by Darren Lim on Mar 10, 2004 2:16:46 GMT -5
Topic 5 - Maintenance (I decided to do this first before livestock)
Hopefully by the time you reach this stage, your tank will have cycled fully. It may not actually be mature yet in terms of stability and being an eco-system, but at this point, your livestock will have started being placed into your reef biotope.
Maintenance is a pretty important part of marine aquaria. Everyone has heard before that maintenance is so difficult, and so on and so forth, but it doesn't have to be too painful, if you're patient and take things slowly. Remember that in a marine tank, only disasters happen overnight. Good things take almost forever to happen!!!
Most of the maintenance relates to keeping your water quality parameters as close to perfect as possible. Most of the common areas that are within our control will be covered here.
Test kits needed :
a) NH3 - ammonia
b) NO2 - nitrites
c) NO3 - nitrates
d) KH - carbonate hardness
e) Ca - calcium (more for hard corals)
f) PO4 - phosphates
This may seem to be a lot, but in actual fact, other than (e), you're supposed to use all these anyway, but most people don't bother since they do weekly water changes. If you're willing to do the same for your marine tank, it's possible that you may not need to test so often too.
1) Nitrogen cycle stability : If you have been patient during the cycling period, then ammonia (NH3) and nitrites (NO2-) should both be zero. Nitrates (NO3-) might be close to zero but not necessarily.
2) pH and KH level. Our SW is generally kept at a pH range of between 8.0 and 8.3; However, it can fluctuate between daylight and dark hours to a larger extent. This happens because during the daylight cycle, photosynthesis occurs in corals and algae which absorb CO2 from the tank, hence increasing the pH. At night, the reverse happens and they release CO2 into the water, which causes the pH to drop. This is one of the reasons why refugiums are sometimes used in a sump or in a hang-on-back filter. These refugia normally contain macroalgae and have a light that runs either on a reverse daylight cycle from the tank, or even on a 24-hour basis. This will prevent the pH from dropping too much.
KH or carbonate hardness performs 2 functions :
a) Enables hard corals, coraline algae to form their skeletons in conjunction with Calcium ions in the water. If you just have high Ca, but low KH, it's not going to happen. Both must be be present in the correct proportions.
b) When maintained at 8 degrees or above, it will stabilise the pH, preventing it from swinging up or down too much. This is a natural property of KH and you do not have to worry too much about how the chemistry works. Just keep it between 8 to 15, and it will be fine. KH can be increased by adding powdered or liquid buffers. But try never to increase the KH
by more than 2 degrees per day.
3) Calcium level - this should be kept within 400ppm to 480ppm, if you have a reef tank with corals. Even without corals, it will help the pretty pink and purple coraline algae to grow on your rocks. Calcium can be increased/maintained in several ways :
a) Liquid additives usually containing saturated calcium chloride - this is very concentrated, and you have to be very careful not to overdose, or it will react with the KH in the water to form calcium carbonate, and subsequently, BOTH calcium and KH levels will drop.
b) KW - kalkwasser or saturated calcium hydroxide solution as mentioned in the subtopic of handling evaporation under the temperature main topic.
c) Commercial 2-part ionic salts
d) Calcium reactor - this is a cylinder containing aragonite or crushed corals. CO2 is dissolved in the water to form carbonic acid which then dissolves the aragonite. This will then increase BOTH Calcium AND KH levels for you.
e) KW reactor - this is a device that simplifies (b) so you don't have to make fresh batches everyday, but at the moment, these are quite expensive.
4) Phosphate (PO4-) control - this is quite an important area to cover. When PO4- levels are detectable in your water, you will usually encounter a green hairy algae outbreak of either Derbesia or Bryopsis. Derbesia is like hair having long thin strands that cover everything. Bryopsis is fine featherlike which will also cover everything.
Sometimes you may not detect any PO4- in your water, but you still have hair algae growing on the rocks. This happens normally because your tank does not have enough water flow, and detritus (powder-like broken-down waste matter or particles) settles in the holes of the live rock. These detritus pockets contain PO4- that are absorbed by the algae and so you can't detect them in the water. Just make sure you have enough current in your tank to keep the detritus off the rocks. Alternatively just before you do a water change, you can always use a small power head and blow off the detritus on the rocks.
If PO4- are in your water, you can use PO4- absorbing resins or just change some water. This is one of the reasons why you still need to change water even though your NO3- levels are zero. KW (Kalkwasser) will also react with the PO4- in the water and can be removed using mechanical sponges.
As mentioned, it is important to change water even when your NO3- levels are zero. This will remove PO4- for you, it will replenish trace elements and minerals, push up the KH and Ca levels, remove other forms of organic wastes that have been missed by the protein skimmer and/or carbon. Some people prefer to use PO4- absorbing resins and top-up trace element and mineral additives, but water changes are usually cheaper, although a bit more tiring (especially if you have a 2000 gallon tank!!).
Algae control - The most commonly encountered algae is brown algae or diatoms. These usually start growing on the glass, and sand, then the rocks. Diatoms feed on silicates which are present in tap water, so if you use distilled water or RO/DI (reverse osmosis / de-ionised) water, this will not occur. However, diatoms are non-toxic, and many of the in-house larger zooplankton like copepods and amphipods actually feed on them. Diatoms can be easily taken care of biologically by using certain animals like the algae blenny, Turbo, Astrea or Trochus snails. Some bristletooth (tang family) will also eat them. If you put a handful of Trochus snails in your tank, usually they will reproduce in your tank, and you can get new generations from there. Of course you can also wipe the glass with a magnet or sponge
Green hair algae as covered above is caused by PO4- usually within LR pockets. You can just pull them out, and this will actually remove PO4- from your system. Some fish like tangs, rabbitfish and foxfaces will eat them, but usually only when the algae is still short. Once they have reached more than 1" in length, most tangs won't touch them (too tough, I think). The rabbitfish and foxface will still eat them unless they're VERY long. In this case, you have to pull out most of it first, then the fish will help you finish off the rest, and prevent new ones from growing.
Cyanobacteria - red slime algae - this is probably the worst kind of algae you will encounter in your tank, and is directly caused by very high NO3- levels, and usually indirectly by a change in lighting at the same time. This algae will coat EVERYTHING in your tank except for the fish !! There is no real cure for it, other than resetting up the tank. It's always better and easier to prevent it by keeping your NO3- low.
Equipment maintenance
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Clean the skimmer collection cup whenever you see anything more than 1 cm of dirty fluid collected. Don't expect it to fill up to the top, it will not, since the dirt at the bottom of the cup will get thicker and thicker thus preventing the foam from rising any further. If your airstone skimmer is producing less foam, change the airstone. If your venturi skimmer is producing less foam, squirt some hot water down the airline tubing into the venturi valve to dissolve the salt deposits there.
Daily, just look at it and the organisms, making sure everything is open fine, and feeding well. Remove any dead organisms ASAP. Make sure all pumps, filters (if any) and other accessories are all working. Topup with FW or KW if your water level has dropped - do NOT wait a whole week to do this, or your salinity and other parameters will be changing. Oh, and feed the organisms if necessary.
Weekly, test your NO3- levels until it reaches zero, then you can test monthly. Also test your KH to ensure it is staying at 8 degrees or more. If possible, change 10% of tank water, or whatever is necessary to keep NO3- under 20 ppm.
Monthly, test NO3-, KH, Ca++, PO4-. Change 25-30% water if weekly changes have not been done.
6-monthly, clean your pumps and powerheads to make sure that the impellers are still spinning smoothly. If you're using FL or PL lights, they should be changed at this point to ensure the intensity remains high. Otherwise, it will start to drop.
9-12 monthly, change 10000K and 20000K MH bulbs as well as T4/T5 bulbs.
18 monthly, change 6000K or 6500K MH bulbs.
Feeding
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Other than standard commercial fish food, you can also breed your own brine shrimp and enrich them further using phytoplankton (not yeast!). You can also blend your own seafood items with some spirulina or nori sheets (just don't let your mum/wife/GF know!). This will provide some variety to your fish. Remember that tangs and other herbivores need more greens in their diet. You can also feed live phytoplankton directly to your tank for certain corals and for the featherduster worms, clams and other filter feeders.
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Post by Darren Lim on Mar 10, 2004 2:17:21 GMT -5
Topic 6 - Livestock
This is the last of the topics that will form the basis of starting a marine aquarium bio-tope.
There is an endless list of biotopes that you can build up, much depending on personal taste and budget. Since personal taste is very subjective, all I can provide will be guidelines on dos and don'ts, with an occasional recommendation. But whichever biotope you use, there will usually be a standard list of organisms that you will want to have, partly to upkeep your tank for you. These are the "Bandaraya" or "Municipal" creatures
For diatom or algae control, you can use the algae blenny, Salarias fasciatus. This looks a lot more cute than the freshwater plecs, and doesn't grow as large. Some of them will even take pellet and other food, when it runs out of diatoms. Be careful when you want to put more than one. Most of them will chase and bite (suck??!!) each other as they are quite territorial.
The bicolor-blenny (Ecsenius bicolor, I think) also eats some diatoms, but it prefers aquarium food!! Other than these fishes, you can also consider snails like the Turbo, Astrea and Trochus. Some people (like me!) have tried Nerites before, but they like to climb above the water line, and most will end up in your hall, bedroom, wherever! Trochus snails will multiply in your tank as long as you have a bunch of them (say, 6 or so, to be sure). In no time at all, you'll see mini trochus crawling around your tank.
Certain fish in the bristletooth family (related to Tangs) also eat diatoms a lot, like the Striped bristletooth, Ctenochaetus striatus. However, they seem to be able to recognise the algae blenny as a competitor, and usually chase them all over the place. The blenny doesn't mind, since he's so streamlined and can slip into any hole he likes anytime
Lastly, certain sea cucumbers (cukes) will also eat diatoms for you, especially on the sand bed and LR. Be sure to get sand-sifting and NOT filter-feeding cukes. The filter feeders are extremely poisonous, e.g., the Sea Apple, if they die in a power head or by other means. Some of you out there will have 1st hand experience of this. These cukes can be recognised by having very fancy feeding mouth parts like tentacles that stick up in the air. The sand-sifter cukes just look like a cucumber or banana or ..... Quite disgusting looking, but useful.
For hair algae control, you can use rabbitfish or foxface (genus Siganus) or the ever-popular tangs (family Acanthuridae). The tangs however are very choosy, and normally do not eat hair algae longer than 1 inch, while the Siganids will. In the wild, you will see schools of large rabbitfish gobbling up hair algae wherever they pass.
Some sea urchins will also consume hair algae when they crawl over the LR surface. There are however several problems with urchins :
a) They may accidentally poke your corals
b) They may knock over your LR if you haven't mounted them securely
c) They normally eat the coraline algae at the same time as the hair algae, leaving white patches.
For scavenging on uneaten food and dead fish that you can't reach deep within the LR structure, you can use a variety of shrimps. The most popular are the boxer or Coral Banded Shrimp (Stenopus hispidus) and the cleaner, skunk or doctor shrimp (Lysmata amboinensis). The boxer shrimp can be a bit aggressive sometimes towards the cleaners. The cleaners serve another function in the tank - as long as you have more than 1, they will ALL get pregnant even at the same time, and produce babies which will serve as zooplankton for your corals and filter feeders like featherduster worms.
Note: In many LFS, the holding tank water is usually of a lower salinity, sometimes even down to 1.018; When you add invertebrates to your tank, you will have to condition them slowly to your tank water first. However, this is also a good practice even for fish and corals. Most people just float the plastic bag in the tank to let the temp. equalise, but this is not enough for inverts. They have to adjust to the different salinity slowly. The easiest way to do this would be to slowly drip in your tank water into the bag. When it's quite full, pour away some of it, and continue, until both tank water and bag water are the same salinity. Then your livestock will stand a much better chance of survival.
For some fish like clownfish (especially the common or ocellaris clown), they're very susceptible to what appears to be fungus/velvet and slime on their body. A good but slow way to condition them is to use hyposalinity. This is usually done by having a quarantine tank with a simple filter - can even be sponge and carbon, since you may have to change water regularly if NH3 and/or NO2 build up fast. Don't worry about NO3- or KH here.
Basically, you need to lower the salinity from the LFS water daily for about a week or so, down to 1.009, but since most of our hydrometers are not very accurate, target 1.010 - it's a lot safer. Once it's reached 1.010 keep the fish there for about 2 weeks. This will be enough time for most external parasites to drop off and "burst" in the lowered salinity. Then start changing water to bring the salinity back up to your main tank salinity, but go even slower than the 1st time. Once in the 2 salinities are the same, ensure that the temperatures are the same too, and place your fish into the tank.
Biotopes :
Fish only - totally up to you - could have a genus tank, with fishes of the same genus like yellow tang, sailfin tang in the Zebrasoma genus, or say a tank of groupers in the Epinephelus genus. You could also do a mixed predator tank of lionfish, moray eels, groupers. Of course, you could keep it simple and have a Amphiprion tank of only clownfish, and even try to get them to breed! For large tanks and impressive fish, many people like to keep angels from the Pomacanthus or Holacanthus genera. Very challenging and quite expensive, but worth it in the end. For a low bio-load and stable environment, try to have no more than 1" of fish for every 5 US gallons of water.
Reef - again totally up to you, but basically try to avoid putting angels and butterflies into this biotope. Most of them would love to take a bite at your corals. If they happen to like it, that coral is gone... kaput ... finito. You can have a community of different fish in a reef tank, and many people like to put damsels in - colourful and cheap. Only problem is, they're sometimes bullies, and it's 99% impossible to catch them in a reef tank.
You can have specialised reef biotopes as well, for instance a shallow-water high-energy setup where light is intense and currents are strong, for SPS corals like Acropora, Montipora, Poccilopora, Porites, etc. Or a calm lagoon biotope with mushrooms, buttons, brains, LPS corals like bubbles, hammers, frogspawn, etc. Or a mid-water high-energy setup with only soft corals instead of SPS corals. Or a gentle hill slope of LR containing only plate corals of various colours. Or an anemone tank with the correct clownfish species in them. A very good mix would Stichodactyla haddoni and the saddleback clown, Amphiprion polymnus, or perhaps the bubbletip Entacmaea quadricolor with a maroon clown couple.
Then again, 90% of reefers keep total community tanks. Typical case would be most LFSs themselves. Their tanks are usually packed solid with corals next to each other, so much so that you can hardly see the LR structure This is definitely NOT the case in the wild. Like fish, corals will also grow and they have nematocysts (stings) that they will use against their neighbours. Some also have toxins that they are very willing to release as well. If possible, try to keep at least a 6" diameter of space between each coral. Of course this means that in a nano-tank, you can probably only have 2 pieces
Coral placement : Most corals do not like being in the path of a full blast of water from a powerhead. They need water flow, but not too violent. You can always turn the powerhead somewhere else to change the flow, or change the position of the coral, or use a piece of LR to deflect/diffuse the water flow a bit. Certain corals do better on sand beds, while others do well on rock surfaces. Plates (Fungia, Heliofungia) and brains should be placed on the sand bed. Most hard corals can be placed in the LR structure. Same thing with buttons, mushrooms and soft corals. These 3 groups of corals will usually stick and spread onto the LR, thus getting larger colonies.
Note : Plate corals will move slowly and if you place it on the LR, it could fall down and kill itself, while releasing thousands of nematocysts. Or it could fall on top of another piece of coral, killing itself and the coral.
Lastly, photosynthetic corals in addition to needing light should also be fed. The food to feed depends on the coral. Those with small polyps will take zooplankton (animal-based mobile), those with tiny polyps will take that and phytoplankton (plant-based, very small), while those with large MOUTHS (like brains) will take solid food and also various types of plankton. Plankton is nowadays available in dead liquid form, dead powder form and live form. If you use the dead forms, do NOT overfeed, or you may encounter hair algae problems or even cyanobacteria outbreaks. Live phytoplankton will not pollute your water and will even multiply in your tank under the right conditions.
Non-photosynthetic corals are VERY hard to maintain since they must be fed planktonic foods almost on a continuous basis. This is normally achieved by having a very slow drip system as in a topup system. These corals are normally the very colourful carnations (Dendronepthya) and the bright orange sun corals (Tubastrea). These should be left to the more experienced hobbyists that have the time and patience to maintain these corals.
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Post by Darren Lim on Mar 10, 2004 2:27:08 GMT -5
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