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 :
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.
An even cheaper alternative - forget everything, and once
a week, just skim off the surface manually using a bathroom scoop (without
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.
Get a hydrometer - floating type, or swing-arm - doesn't really matter, most of them aren't very accurate anyway!
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
Get about 17-18kg of #0 or #1 crushed coral or beach sand or even crushed white marble (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 "Nemo" (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.
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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