Every time you change the water in an aquarium that contains tropical fish, you create stress for the fish, so the lower the maintenance requirements of your tank, the less stress for your bettas. To create a self-cleaning betta tank, simply establish the proper ecological balance and start with the right equipment. Bettas are tropical fish that thrive in warm water.The warmth of the water can promote growth of algae, so you need a simple strategy to keep it under control. Bettas thrive best in a relatively shallow to 23 to 90 litre (5 to 20 gallon) tank. Take a few simple steps and you will have a low-maintenance beautiful tank.
Install a power filter into your tank. A power filter uses replaceable carbon-filled cartridges that remove impurites from the water as it is circulated through the filter. The carbon helps to remove odours and prevent discolouration even as the filter removes solid impurities. Make sure to check when you buy the power filter that it matches the size of your tank. If you use less than a 23 litre (5 gallon) tank, you may have to use a more basic type of filtration system. The cartridge should be changed every three to four weeks.
Get one or more algae-eating fish and add them to the tank. The most common is the plecostomus, which looks like a miniature catfish. These fish thrive in tanks that get sunlight, which stimulates algae production. That in turn keeps your plecostomus healthy and happy - as he keeps your tank clean. The rule to follow in tank size is to have 4.5 litres (1 gallon) for every 2.5 cm (1 inch) of fish. A 23 litre (5 gallon) tank can easily support two bettas, two other small fish and a plecostomus.
Do not overfeed your bettas. Bettas have small appetites. They only need to be fed once a day and they should be able to finish eating what you feed them within two minutes. Overfeeding them will leave the tank cloudy and can cause the fish to produce more waste than is healthy. Carefully read materials on how much food to use for the number of fish in your tank.
If you have to change the cartridge in the power filter more than once every three to four weeks, it could be a sign that you are overfeeding the fish. Make sure to keep up with cartridge changes. If you let it sit after it is due for a change, the water quality in your tank can deteriorate rapidly, becoming both cloudy and smelly. It is common to see bettas in very small tanks, or even vases. As pretty as this can be, it does not provide an environment that will support bettas over a long term, and it is very difficult to create a balanced, sulf-sustaining ecological habitat in such small containers. The larger the tank, the easier it is to create a self-sustaining environment. Keep a skimming net handy so that if anything large accidentally drops into the tank, you can easily remove it without letting it go through and clog up the filter.
Having a self-cleaning tank does not make it a no-maintenance tank. You still have to change the filter regularly, keep the temperature set properly and make sure it gets enough light. Over time, the plecostomus can become quite large. If the pleco gets too large you may want to transfer it to a secondary tank and get a new, smaller one for your betta tank in order to keep plenty of room for your bettas.