A common problem with new fishtanks and new fishkeepers is that once the tank is "setup", people think that the work is done. Even though the tank looks set up, you're only half way home.

Now, you've got to get the water and the filters ready for the fish. Not only do the filters remove visible debris from the water; they also remove the poisonous chemicals from the water. The charcoal in the filter does a pretty good job of absorbing most of the toxins, but a big player in the filter process is the nitrifying bacteria.

You need to start growing a colony of bacteria to process the ammonia in your tank. Fish waste and dead plants breakdown into ammonia. The only way to keep the fish from being poisoned to death is to have and established filter of bacteria to break the ammonia down into poisonous nitrites. Of course, there are also bacteria that can break down the nitrites into nitrates. Once you're there, the fish are happy.

Oh, You've never cultured bacteria before? Don't worry, they'll grow on their own, given the right conditions. You can use some "feeder goldfish" as starter fish to get your tank going. Most pet stores sell cheap goldfish to fishkeepers as food for larger carnivorous fish. One of these guys for every 10 gallons supplies enough waste to get you going smoothly. You might consider some danios to do the same job. They aren't as dirty as the goldfish, but you can keep them in your tank with your tropical fish. The goldfish will have to be deported, as they don't make suitable tankmates for your tropicals. I bought 3 "feeders" for $0.10 each. They'll get moved to the pond in a couple of weeks.

It's best to have a test kit to monitor the ammonia, nitrate, and nitrite levels. Using your test kit you can watch the ammonia level rise until the bacteria starts eating it and producing nitrites. Next, you'll see the nitrite level peak and then start to fall. That's the sign you've got the right bacteria to process the nitrites. Finally, you'll see the nitrate level start to climb. The nitrates are relatively harmless to the fish. Doing a 20% water change every couple of weeks should keep the nitrate level to a reasonable level ( in your tank and wait 3-4 weeks. After that, you should have a cycled tank.

Learn more about this author, Jack MacDowall.
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