Setting up a New Aquarium

I was surprised several times along the way as I learnt about fishkeeping. I had learnt that you need air pump, filter and heater, and expected this to be expensive and fiddly, so I was delighted to find that you can buy tanks with everything built into one core, and bought a Juwel Rekord 70 (70 litre basic tank, everything inbuilt). Otherwise you need a filter, a heater, and light (and ideally timer switch for it). As well as filtering the outflow also aerates the water, by moving the water surface - this causes oxygen to be dissolved into the water. You can also buy an airstone and airpump if you want to see bubbles in your tank, but this only increases aeration by the extra surface movement, so it's optional. Just make sure your filter outflow makes the surface move, when you set the tank up. I was also not told about thermometers, but as the calibration on heating elements will vary, you can get a cheap tank thermometer to stick to the outside of the glass. A small net is also useful.

However I had thought it would be easy to get going once I had all the equipment sorted out - I had not realised that you need to mature the tank first (see below) before you can even think of putting fish in it - so you will need to be patient!

Also, think about where the tank will go. Even small tanks are heavy. If you do not wish to buy a recommended stand or cabinet, choose a solid piece of furniture to support it (a good test is to sit on it!) and ensure that the top is also strong enough. I bought an MDF board which was cut to be slightly larger than the top of the furniture, and then painted to be water resistant. In that way the furniture was protected from water damage, and also from the fishtank going through the top.

Check the orientation of the floorboards, and make sure that your tank will stand along the joists (at right angles to the boards), so that you do not risk the tank going through the floor. This is unusual, but it is worth being careful especially with older floorboards or with tanks 3ft and over. Larger tanks should also never be placed upstairs. If you can stand the tank on a concrete floor, that's even better. The tank should also be against a wall rather than in the middle of the room. Vibrations from people walking past etc. can be surprisingly bouncy and the tank will be more stable against a wall.

Maturing the tank means establishing it so the water is not fresh out of a tap, and so that there are natural biological cycles going on within the filter. It's also called "cycling" the tank. It means establishing the nitrogen cycle within the tank, so the fish's waste is converted from toxic ammonia to nitrite and finally to nitrate, which is harmless.

To begin with, put your tank in place according to the instructions, installing your light, filter and heater, but don't turn them on. Add gravel, rocks and so on. You can add plants now, or when you buy your first fish. Fill with water, and treat the water with something like Tetra Aquasafe, to remove chlorine and other harmful chemicals. If you can get the water to around 25°C, it will mean that the heater has less work to do.

Now, you can turn on your filter and heater. This will begin pulling water through the filter, and bringing the water to temperature. You can add a bacterial treatment to aid the establishment of bacteria in the filter - but there is some debate as to whether this helps. If you have access to a friend's established tank, you can "seed" the tank with bacteria to kickstart the process (read beating the cycle) - otherwise don't worry. Time will do all the hard work!
There are then two ways to start the cycle in the tank. After a week when the water in the tank has aged and the equipment has been running so you know it works, you can either start things off with a few fish, or you can do it by adding household ammonia to the tank to mimic fish waste products. To read more about the fishless cycle there is a basic guide here. I will however describe cycling with fish.

Firstly, get a test kit. You'll need to test for ammonia and nitrite at the least; getting a kit that also tests pH and nitrate is good. Now you can consider adding fish. However, don't just get any fish - at this stage you still need to get hardy fish that can survive difficult conditions, and then their presence (waste products breaking down, and so on) will mature the tank before you can add other fish. Ask your aquarist to recommend suitable fish - Barbs and Danios are good for this. However, both are active and some barbs will attack slow moving fish or those with long fins, so already you are limiting your future choice of fish. I decided to start with half a dozen Black Ruby Barbs, and they have survived a range of conditions in the tank.

When you introduce the fish, first leave the bag (still tied) in floating in the tank for ten minutes. Then untie, get a cup and add a cup of tank water to the bag. Leave for another ten minutes being sure that the water in the bag has its surface exposed to the air. Finally net the fish and gently introduce them to your tank; do not tip the bag water into your tank as you may introduce disease.

A month later, use a test kit and check water quality for pH, nitrite and ammonia. If all is well, go ahead and add fish. If ammonia is high, you have a long wait ahead; it will peak first and then come down again. Then nitrite levels will peak before falling. Wait until they are both nil before you add more fish. But don't even think of adding algae-eaters (like Plecos) until you have a good two months' build up of algae all over the glass. My local pet shop said "Ah, he will always find something to eat in there!" but they are called algae-eaters for a reason. They will also attack plants if hungry!

When you are ready to learn more about cycling the tank, there is an excellent guide at TheKrib. I have also written a guide about beating the cycle for aquarists with access to an established tank.