Originally Posted by pleechford
I am having a sudden spike in nitrite and ammonia (ammo is almost under control) The nitrite is at 5ppm. Is this really harmful for my fish and plants?
Yes it is very harmful for your fish. It will cause nitrIte poisoning.
You should read up on fish-in cycling: I just learned about cycling but I already have fish. What now?!
The cause of this is because you are doing the nitrogen cycle in your tank, fish and food cause Ammonia, which is converted to NitrIte and ultimately converts to NitrAtes. Cycling produces beneficial bacteria that will convert the fish waste quicker than the waste can hurt your fish. You seem to be in the NitrIte spike phase of your cycle. The way you will keep your fish alive is by doing daily water tests and changes, maybe even twice a day.
I would do this: 50% water change, wait 1 hour and do another 50% water change. Test your levels, if you have anything over .25 NitrIte or ammonia, do another 25% water change. Judge your water changes by the testing kit. Meaning if you have .25 ppm
do a 25% change, if you have a .5 ppm
do a 50% change, etc. You're going to have to keep the levels down by doing water changes. Don't go to a store and believe that the chemicals will do anything, because they won't. The only thing you need is clean water and a good water dechlorinator like Seachem Prime. Prime will help you keep the fish alive because it will DETOXIFY the nitrItes for you for 24hrs, NOT remove them.
Good luck and keep us posted, if you put in the work your fish should be ok.