# Fishless cycling ( nitrogen cycle ) of aquariums



## FishlessCycle

I assume most people have heard of the terms such as *nitrogen cycle* and *fishless cycling* when it comes to aquariums.
It is the process of ammonia is converted into nitrite and then into nitrate.

An aquarium hasn't completed the nitrogen cycle can't support any fish. 
To keep fish safely and healthy, a fishless cycle is highly recommended. That is, to cycle the fish tank without fish.

Out of all the methods of fishless cycle, it is the best to use pure ammonia with heavy seeding of live bacteria. Many hardware stores sell pure ammonia. Whatever you buy, make sure there is only ammonia and water in the product.

By seeding the live bacteria, you can greatly reduce the cycling time from typical 6~8 weeks to as short as a week or two. The best thing to use for seeding is a piece of filter media from an established tank. If you do not have access to that, a live bacteria product called Tetra SafeStart works fine too for a jump start. It is the only proven working live bacteria product out there at the time I am writing this. Many other such products won't work because they have the wrong type of the land based nitrogen cycle bacteria which will die in the water.

For full instructions of *fishless cycle* with pure ammonia, read fishless cycling ( nitrogen cycle )


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## SilverShaded

I disagree, provided the tank is of reasonable size, i much prefer to cycle the tank with a small number of fish. Kick start the filter with gunk from an old filter or hagen cycle has worked well for me. The trick is use a small number of fish and increase gradually and feed sparingly, healthy fish can go for weeks without food so dont overfeed and use a large filter.

After 5 months my latest new tank has had no fish losses, not even the fish fry due to water quality, the ammonia and nitrites where never at a dangerous level, several pairs of fish are on the second or third brood of fry and the filter is now reducing nitrates to less than 10ppm. Water changes are now only neccesary to reduce phosphates, so not very often basically.


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## Yomper

Both ways will work as above BUT using fish to kick start the biological cycle can harm the fish. ok the odds are if you stick with just a few fish it would be fine but the fishless cycle is the4 best way. I mean is it worth risking fish lives even if it is just a few mollys etc just to save a week or 2. also if the gunk from an old filter is used its possible any diseases which or if may have been in the donor tanks filter may pass across


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## SilverShaded

I cycle with real fish, not sacrifical mollies and have never lost a single fish due to ammonia/nitrites while setting up a tank. 

Secondly, there are also dangers with adding ammonia directly to the water with fishless cycling, if you dont get the level of bacteria correct in the filter you will have an ammonia/nitrite spike anyway when you do add the fish, and if your ammonia / nitrite test kit is faulty, you will have dead fish as soon as you add them.

At the end of the day both methods work or dont work depedning on who is doing it and neither method is flawless.


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