You've spent a lot of money and time picking out the right fish for your aquarium and you think you've got it just right. Then you start losing some valuable fish. How does this happen and what can you do to prevent this tragedy?
There can be a lot of reasons why your fish are dying. Generally, it happens when a fish tank is new. It pays to buy an aquarium water test kit to determine how much ammonia, nitrites and nitrates are in the aquarium, and how high or low the pH is. These are the four most important tests for your tank.
In the nitrogen cycle of the fish tank, an important biological cycle, the fish give off nitrogenous wastes when they eliminate and these products break down into ammonia, which is very toxic to most fishes. In aquariums, this nitrogen product can build up into levels that are harmful to your fish. When you measure the ammonia level, it should be negligible.
The nitrogen cycle, is the process of getting rid of ammonia using nitrifying bacteria that convert the ammonia to nitrite and then to nitrate, which is not as hazardous. The cycle goes from ammonia to nitrite to nitrate. These bacteria are present everywhere and establish themselves eventually in your fish tank as soon as the ammonia builds up. It is a slow process, however, and you can lose fish in the meantime.
One way of improving the nitrogen status of your aquarium is to purchase an EcoBio-Block Products that contains the nitrifying bacteria within the block. You rinse the block and soak it in chlorine free water over night before placing it in your tank. Normally, in a few weeks or so, you can have your ammonia levels drop followed by drops in nitrite levels. You can safely put your fish in then and expect that they will survive.
The other thing is to take a couple of hardy and cheap fish and put them in your tank. Don't overfeed the fish. More food means that more ammonia will build up. For freshwater fish, try some zebra danios or some barbs. For saltwater tanks, use damselfish. Don't use feeder fish for your tank as they can introduce unwanted diseases in your tank. The initial cheap fish you put into the tank get the nitrogen cycle going and you can then add more delicate and expensive fish to your tank.
Use your test kit to determine the ammonia, nitrite and nitrate level in your tank and use this as a guide for how healthy your tank is. It takes time for the bacteria to develop unless you are using a EcoBio-Stone to speed up the nitrification process.
Poor pH can also be a cause of a loss of fish. The pH is a measure of how acidic or how alkaline a fish tank is. Ideally, the pH should be around 7.0, which is "neutral". However, fish can generally tolerate pH of 5.5 to 8.0. You can get a test strip to measure the level and if you need to change it, look at ways to change the pH slowly.
If your water contains buffers, you will not be able to change the pH very easily. Remember, too, that fish can tolerate a wide range of pH levels but do not tolerate sudden changes in pH. Sometimes it's better to leave the pH alone as long as your fish are thriving.
If you still think you need to adjust the pH, one way to lower it slowly is to add some driftwood to your fish tank or to the tank. A cleaned off seashell or coral skeleton will gradually increase the pH of your aquarium. The downside of both these solutions is that they will stain the color of the water brown or yellow for quite a while, but it will alter the pH in a safe way.
Maintain your tank well and you can have a healthy, happy fish population.