Neons keep dying.

[NetBelleAnie]

I have a 7 gallon tank and a 10 gallon tank, and will soon have a 20 gallon setup. When I first had my neons, I had 3 of them with 2 corydoras catfish, a guppy and a female betta in the 7 gallon. When I got the 10 gallon and another 5 neons, I moved the original three into the 10 gallon along with the corys, guppy, and got a small pleco. I added various plants and some water-soaked driftwood and used some gravel from my other tank and everything was good.

At first I thought everything was ok, but I started having them dying, including the three I had for several months. I did water tests and found the ammonia, nitrite and nitrate levels were low. The last of my neons died while I was away for the weekend.

Any idea why they would just keep dying like that? I want to get some more since I find them really entertaining, but I don;t want them to have the same reaction to my tanks.

I did find eggs in my tank and later a cory fry, but I have not seen any spawning activity since then.

[cocoa_pleco]

by "low" ammonia do you mean you even had a bit? you should have 0 ammonia.

if you dont have ammonia, maybe you keep getting neons with neon tetra disease which is spreadable and uncurable

[smaug]

neons are a fish with a very low constitution for poor water.Any pollutant seems to pick them off.Like was already mentioned your ammonia needs to be 0 as do your nitrites.PH is also important for neons and 7.0 or lower is definetly best .Lets us know exactly what your water params are so that we may be of better assistance to you.

[Lady Hobbs]

Any level of ammonia or nitrite is toxic and those little guys can't survive in it.

[NetBelleAnie]

I guess I forgot to add some info (my bad)

At first when I had the tank setup, I also had m male betta (now known as Mr Bastardfish) in the tank. The tetras were doing fine but I kept noticing that one per day would die, usually with a bite mark on their stomach. I realized it was the betta, so he went back in his own bowl. After that, they weren't dying so much, but after another week they started dying again, also with bite marks in their stomachs.
Now that I know that even the tiniest ammount of ammonia will kill them, that explains the ones with no marks, but what about the ones with bite marks?
Again, my tank was 1 guppy, 2 albino corydora catfish and 1 pleco, though as time went on and the tetras kept dissapearing, I got a second guppy and 2 more corys

[kitten3326]

Maybe you have an aggressive guppy, not unheard of, my dad had a guppy that chased and bit everything in the tank, had to have a tank of her own to live out her days, could not put anything in with her. Weird eh!