Originally Posted by omgPlaty
Unfortunatly, when I got the tank a month ago I did not know about cycling. So, my tank is still in the cycling process. My ammonia level spiked like normal and has now been zero for about two days and nitrites have gone up to 1. (So, my tank has been cycling for a month on the 15th)
We originally had three platy. One of them gave birth and only one fry survived while the two of the adult platy didn't make it. They were found dead several days apart without any phsyical symptoms the days before.
The Fry is still alive. He is a very good hider and we mostly see him at night when he sneaks out for food. He seems fine; he has gotten larger, is very orange and swims really fast.
I'd say the problem is the cycling of a new tank. Some fish can live through it, others can't. (I forgot to ask the tank size, but doesn't matter.) The nitrite reading at 1 is the second phase of the cycle. If you are able to get to a fish store, I would recommend you buy a bottle of "Cycle" and dose the tank according to the instructions for a new tank (it's impossible to overdose, but just use what they recommend, no point in wasting it). A small bottle will do, you use one capful for each 10g now, and then in one week the same. The second dose probably won't be needed, the critical time is now. "Cycle" contains bacteria to "seed" the tank and get the bacteria cycle going immediately. That will reduce the stress on the fish, although the odd one may be too far gone to save. A partial water change of 25% might help save the fish, but don't vacuum the substrate or clean the filter as that will remove the bacteria you are trying to establish.
In the event they all die before you get the Cycle, do a partial water change and start over. It's better to cycle without fish, you can use fishfood to do this, or add pure ammonia (must be pure). I've never done the latter. There are other threads on this forum that explain fishless cycling. If you have fish in the tank, add the cycle when they first go in. It is possible to cycle the tank with one or two fish, using the cycle; i have done this and never had any signs of stress with the fish, but don't do it without Cycle. The bacteria start to multiply and consume the ammonia and a second bacteria the nitrite. The bacteria will multiply according to the amount of food (ammonia and nitrite) that is available to them, and ammonia is produced by fish respiration and such, or by decaying fish food if you use that method.
Once you can test for several days and get a reading of 0 for both ammonia and nitrite, the tank is initially cycled. Then you increase the bioload very gradually, the bacteria multiply as their food increases, and so forth. After 8 weeks the tank is usually considered "cycled." You can then add more fish but only one or two at a time if the tank is small, say 20g or under; if over 20g, you could add a few more and use Cycle each time.