JakeTeque

I am having trouble finding information on what nitrite and ammonia PPM levels are considered dangerous for fish (cichlids) I have a 55 gal w/ 2 Oscars and I thought the tank was completely cycled but nitrite levels are reading .25 ppm right now. I have been doing frequent water changes just to be safe, but the nitrite levels keep going from 0 to .25 a couple days after a water change.

Can anyone tell me what ppm levels are considered dangerous for ammonia and nitrites? Also, when are these nitrates going to kick in and keep everything else at 0?

Thanks everyone!

Shawnie

hi jake!! any levels other than 0 are dangerous...and the tank could have been cycled but oscars are big big pooopers and could have set you back to a cycle if you arent doing water changes at least every other day...the tank is overstocked as mine is and thats what you need to do to keep the readings ammonia and nitrite 0 and nitrates under 20...get some prime if you can, that neutralizes everything for 24 hours until your next water change..goodluck!!

jdhef

Any amount of ammonia or nitrites are toxic to fish. The only safe amount is zero.

The nitrates do not keep ammonia and nitrites at zero. There is bacteria that converts ammonia into nitrites and there is bacteria that then turns nitrites into nitrates. When you have zero ammonia, zero nitrites and some nitrates you are fully cycled.

Lucy

I agree with the above Shawnie and John.

Do you have ammonia readings?
Are you testing for nitrates? What are they?

If you have 0 ammonia and some nitrates you're cycle is almost done, since you still have nitrite readings.

JakeTeque

Ammonia is at 0ppm. I don't have a nitrate test kit at the moment, but will get back to you on that.

If I do a water change will that prolong the cycle? Isn't it possible once a tank is cycled to not have to do a water change for 1-2 weeks? And is my tank really overstocked if the Oscars are juvys?

Thanks so much for your help!

jdhef

It will prolong the cycle, but it will keep your fish safe. You will need to do a partial water change whenever your nitrates get to 40ppm. (Some people may say less than 40, but the API test kit recommends 40 and below). So it could be two weeks, but with you having fish with a heavy bioload it will probably be more often.

Shawnie

2 oscars in a 55 gal tank, as juvies, would be ok for maybe a few months...BUT ..you have way more in that tank as your info says...and after a few months, just the two would need every other day water changes just to keep the nitrates down...I have two 11" ones in a 75 gal and to keep my water parimeters to ammon and nitrites 0, with nitrates under 20, I have to change 50% every other day...your way more overstocked and its not the size of the fish now, its their size as adults and the bioload (poop & waste) that they put out that will kill them if you dont update the tank or change water often...

Barbrella

Agree with Shawnie.

Your fish are juvies: How big are they? Unless you're planning to upgrade to 125 gal tank for your two Oscars, you're looking at nitrite/ammonia poisoning, things like Hole-in-the-Head disease and/or all other problems caused by too much fish in a too-small tank.

Certainly not 2 weeks - not in a tank that size with fish like Oscars. When you upgrade, you'll still need to do once a week WCs.

Red1313

K this may seem like a dumb point but isn't Nitrite, NO2-, what's toxic? I could be wrong but that's what my test kit book says. (I'm in the middle of a water test right now, that's the only reason I'm bringing this up.)

Also since I've got the book out. I don't have a API test kit so this may be different from what your's says but "if NO2 is close to but < 0.3 mg/L (ppm) it's "safe" but should be tested again in 24 hours. To ensure levels aren't rising."

As a side note depending on what your pH is it will effect the toxicity of both NO2 and ammonia.

This isn't going to help you fix any underlying issues but I thought that you may find it useful, and yes the best place for NO2 to read on a test is zero.

Lucy

That's not dumb. Yes NO2 is nitrite and it is toxic.

Red1313

It says Nitrate in the title. That's all I was refering to.

Lucy

This was the op's original question.

Edit: I know a few times when I've mistyped nitrate for nitrite, I guess it was a typo since they're not showing nitrAtes yet.