Fishless Cycling can reduce the amount of time it takes to cycle your aquarium. The keys to this method are water testing and the removal of chemical filtration media.
I did, and that is still true. What you are going to add is pure ammonium hydroxide. This process is all about balance, much like putting a gorilla on a unicycle. Below we will discuss how to use the fishless cycling process to put Mother Nature to work for the health of your little friends.
If you have not already read it, go to the Nitrogen Cycle page to understand what this process is and why you have to do it.
This chemical is the active ingredient in household ammonia cleaner. Most cleaners that use this chemical have detergents and scents added. You will want to avoid these products.
The best source for this chemical is a discount store or hardware store. Usually, the no-name generic brand will be the one you will want to use. The bottle will say pure ammonia, 100% ammonia, or pure ammonium hydroxide on the label somewhere. If no ingredient list is present, do not use that product. Once you find a product that seems to be right, shake the bottle. If the liquid foams, then a detergent has been added and you don't want that one. Pure ammonium hydroxide will not foam.
By now, you should have had your aquarium set up and running for 24 hours. The tap water you added should be chlorine free. Remove any filter media that contains carbon. This will keep the ammonia that you are going to add to the tank in the water supply for your bacteria to eat.
Add 5 drops of ammonia per each 10 gallons of water in your fish tank. Wait about a half hour so that the ammonia mixes well. Then add a favorite product of mine, Stress Zyme, as directed on its label. This product contains live bacteria and will seed your tank and biological filter for the fishless cycling process. Most pet stores that have fish will have this product as it is very popular.
When you go to the pet store to get the Stress Zyme, also pick up a water test kit that tests for ammonia, nitrite, and nitrate. Dip stick kits are less accurate than the kits that have test tubes and chemicals, but they are easier to use and may be better for the fishless cycling process because you are going to test the water every day for about a month.
After you have added the ammonia and Stress Zyme, wait a day and add ammonia again, as you did above. Repeat this daily until your test kit tells you that there is nitrite in your water. When you see this, start adding 2 drops of ammonia a day per each 10 gallons in your tank.
After a few days, you should start seeing nitrate showing up in your daily water testing. Your water testing should show that you have zero ammonia, zero nitrite, and a reasonable amount of nitrate in your water. This is the target water quality.
Stop adding ammonia and do a 50% water change. After adding your water, make sure that the water conditioner you use to remove chlorine does not also remove ammonia. This could cause your new bacteria to die off at the worst possible time, because you are ready to add some fish.
Good fish to add at this point are danios, tetras, barbs, or guppies. Don't add to many, one or two is fine. If you add to many, you will overload the new bacteria colony in your aquarium and things will go south fast. After you add your fish, wait a day and then put your chemical filter media back into the filter system. Continue to use Stress Zyme as directed on the label.
At this point, the fishless cycling process is technically complete. But remember, the system is a balance and is very new. That means it is fragile and you don't want to push things past the tipping point, otherwise your gorilla will fall off its unicycle and all the fish will die.
Wait a couple of weeks before adding more fish, and definately don't add a little friend you don't want to risk until nearly a month after you start this process. Cycling normally takes up to six weeks, but using this method can have the Nitrogen Cycle running in as little as ten days. Don't count on that though, because overloading the bacteria with a large bio-load of fish can cause spikes and you will have all kinds of trouble with fish loss.
One last tip, during this process do not add chemicals that say they will reduce the ammonia content of your aquarium. Many additives are on the market just for this purpose. I have found that if I am in a situation where that I need a chemical like that, I have too many fish in the tank. You might have to take a fish back to the pet store. Adding Stress Zyme is better than adding an ammonia removal product, especially during and just after cycling your aquarium.
For more detailed information, see the Wikipedia Fishless Cycling page.