Why do this?

fishlore101

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Feb 24, 2006
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Why do you have to cycle a tank before you put fish in? This is the first time I have never heard of this. Most people I know (myself included) never have done this and are fish are healthy. The tanks are set up a day before fish are put in. I have talked this issue over with all my friends who have tanks and they have never heard of it. (I know that it is for the growth of good bacteria.)
 
well first off, you buy fish to put in there to cycle it, alot of people buy hardy fish and expect to loose some of them from the cycle, and think of these fish as expendable. Most people on here don't think that any fish is expendable and since you can get the same results from using ammonia without taking a chance on hurting or killing fish. also with using ammonia, you can fully stock your tank when the cycle is up since it will be heavily seeded with the bacteria (if you use enough ammonia). you can fishy cycle, but if you don't monitor the water quality and do water changes quite often, then even if your fish live, they are likely to be damaged from gill damage from high exposures from ammonia / and problems from nitrite and their life expectancy will be lower and might suffer from infections / diseases from a worn down immune system. i have fishy cycle my tank because i can't the right ammonia where i'm from, it all has soap around here. but i've also done up to 3 50% water changes a day, at times. i hope this info has made you aware of some of the problems associated with fishy cycles and if you are going to do one, be prepared to do a lot of work to keep your fish healthy.
 
Cycling a tank means that you allow time for the growth of certain nitrifying aerobic bacterias to take hold in the system.

What these bacterias do is consume ammonia and nitrite in order to turn it into less harmful nitrate.

Ammonia is present in the waste products of all the creatures you have living in the tank, as well as in any dead things or uneaten food. The problem is that in a brand new tank, there is no bacteria present just yet that will consume this stuff and turn it into nitrite. In time, with the ammonia food source, this bacteria will begin to grow and multiply. Thus you get the next part of the cycle -

Nitrite. This is the by-product (waste) of the ammonia eating bacteria. Eventually this stuff (less toxic than ammonia but pretty darn deadly) will build as the ammonia eating bacteria consume the ammonia and make nitrite. Thus after the ammonia eating bacteria has started to produce nitrite, we must wait for the nitrite eating bacteria to appear. (This is often a little longer than the ammonia part of the cycle.) Once the nitrite begins to decline, then comes the last part of the cycle -

Nitrate. This is the least toxic component, the by-product of the nitrite consuming bacteria. This stuff generally isn't harmful to the fish so long as it stays below a certain level. Being as the the bacteria that consume this stuff are anaerobic, you would generally not find much of it in a healthy tank. That is why we do scheduled water changes. That is how we keep nitrates down to tolerable levels.



In order to "cycle" a tank you basically either feed a continuous amount of ammonia (what is known as a "fishless" cycle) until all of the necessary bacteria becomes present, or you put in a few small hardy fish who can survive the stress of the cycle. You generally will not add any more until the cycle is complete. Test kits for ammonia, nitrite and nitrate are essential in order to keep track of a cycle and know when it is safe to start adding some creatures.


I cycled my tank once with two zebra danios. I still have one of them, three years later. (The other died about a year ago.) So I'm not so sure about there being significant permanent damage to strong fish who have been put through a cycle.

But would I cycle a tank with a discus? Not bloody likely.

So in regards to those who have never heard of, or don't practice such a thing...well, they do it even though they don't know they do it. I assume that filling a tank with fish, and then losing several of those fish doesn't ring in their head as unusual. So eventually the tank becomes cycled simply because nature takes its course...but that doesn't mean you should ignore the cycle and take such a chance with the lives of other creatures. Fish are so inexpensive that we materialistic Westerners tend to value their lives on monetary cost. I find that tacky.

Cycle your tank properly if you can. Just add one or two really hardy fish, or learn the fishless cycle. Don't add any more until all is in order. Your fish will thank you, and you'll save yourself the monetary and emotional hassle of dealing with dead fish.
 
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I don't think he/she understands the cycle itself. The tank will "cycle" if you put anything in a tank that produces waste. This cycle also happens with normal life out of water. Waste is ammonia. Once it's in the water. Bacteria will consume it and their waste is nitrites. A different bacteria converts it into nitrates. You need to have enough bacteria in your system to eliminate the ammonia/nitrites that are made. There aren't any bacteria that will consume nitrates in a freshwater system. So, you need to do water changes and clean the gravel to keep the nitrate levels low enough that they don't poison your fish.

Kim
 
Wow info overload. Thanks for all of the great information. I will share all this with my friends. Thanks again for the help. :read:
 
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