Cycling a New Freshwater Fish Tank

I grew up with fish tanks and then worked at a pet store that catered to fish enthusiasts. One of the biggest mistakes I saw new tank owners make was not cycling a new fish tank before adding fish. We got a lot of people complaining that their fish were dying, only to find out it was a 3-day-old tank.

What is Cycling?

Cycling creates an environment of good bacteria on your filter, a new tank needs it to support fish and keep the tank healthy.

The waste from fish and excess food will break down and turn into ammonia. The bacteria in the tank will help turn the ammonia into Nitrite and then into Nitrate. Nitrate is then removed from the tank when you do your regular water changes.

This process can take anywhere from 2 weeks to over a month. You need to be patient and let the process take its course. Once the tank is established, you will have very little trouble with it.

How to Cycle a New Tank

There are a few different methods you can use to get the bacteria growing and jumpstart your tank.

Adding fish. Putting a few hardy fish in the tank will start things. I would suggest using a few Mollies, they're a hardy fish. You don't need a lot, 2-3 will be more than enough to get a 30-gallon tank started. This is not the preferred way to cycle because it puts the fish under a great deal of stress and sometimes disease can emerge because of the stress.

Fishless cycling. This involves knowing someone else with a fish tank. You can get some of their wastewater, from a water change, and pour it into your own tank to get the cycle started. You need to be careful when using this method, you will inherit any diseases or water problems that come with it.

Chemical cycling. There are a slew of products out that will help you cycle your tank. If you decide to use any of these follow the directions word for word. You will also want to do regular water testing. Chemicals will cycle a tank just like nature, so you should be able to observe a rise in ammonia, then Nitrite and Nitrate. One of the best to use is Biospira by Marineland, I've used it many times to start up new tanks and never had a problem.

Tips

Do not add a bunch of fish while your tank is cycling. It will only stress them out and you will loose most of them. You want to stress your fish as little as possible.

Make sure you monitor the ammonia, Nitrite and Nitrate levels. If you test your water every other day, you should be able to plot out the rise in each.

Once your tank has gone through it's first cycle and all levels are back to an acceptable range, you're ready to start adding fish.

But that's another article. Have fun and enjoy your tank.