HELP!! - NH3/NO2 Spike in QT tank

[MommaFishels]

I have a small NH3 and NO2 spike in my 20 gal QT tank (~0.25 ppm NH3, ~0.5 NO2), currently holding an orange spot sleeper goby and a Bangaai Cardinal. I only have 3 gallons of ready to go mixed up saltwater on hand, left over from my weekly PWC yesterday. I doubt 3 gal is going to make that much of a difference and it will be ~24 hours before the next batch is ready to go.

I'm about to go down and do the 3 gal water change, but what else can I do before the new water is ready to go tomorrow? I have Amquel+ on hand, should I add some of that to neutralize the NH3/NO2, or is it best to wait it out until tomorrow?

I do not currently see any outward effects on the fish, no odd behavior, no rapid gilling, etc.

[MommaFishels]

~3 gal PWC has been executed. Still no strange behavior from either fish. New 10 gal batch of water mixing up now. 50% PWC scheduled for tomorrow.

Still at a loss for what to do (or if I can/should do anything else) since the new batch of water won't be ready until tomorrow.

[Kurt_Nelson]

Sounds like you're doing all you can for the moment. I'm not sure I'd get as aggressive as a 50% change - I'd probably stick with 30% changes at the most, and do them a couple times a day if you have to.

I'm thinking these are new inhabitants to your QT, and the QT was cycled if I remember your posts correctly? If so, then your biofilter is just catching up with the new increased load, and you should drop your ammonia/nitrite levels down to zero within a week. Just stay on top of the test results and keep a fair amount of water ready to go.

[MommaFishels]

Yes, you are correct in that the QT is already cycled. The 2 fish in there now should be an increased bioload over what was there before (2 PJ Cardinals). In addition, them not eating for a few days didn't help I'm sure. I tried to get as much of the uneaten food out as I could, but you can never get it all.

I'll proceed with a 30% change tomorrow. I was under the impression that ANY ammonia or nitrite was not good and cause for great concern, hence the apprehension and panicked posting. Thanks for the advice.

[Kurt_Nelson]

You are correct... any ammonia or nitrites is a bad thing. But, compounding that with sudden changes in pH/temp/salinity can make a bad situation worse. It's a fine line to run... and you just have to use your best judgment based on how the fish are reacting. With your fish displaying no obvious problems, that's the only reason I'd opt for smaller - maybe more frequent - water changes.

I've ridden out ammonia/nitrite spikes with my QT also, at the levels you mention. I also didn't see any issues with my fish, but that still didn't keep me from worrying about them and doing daily water changes. Pretty helpless feeling, but once that ammonia hit zero, I'm sure the neighbors heard my loud sigh of relief! Hopefully it'll work out fine for you too... by the sounds of it though, it sounds like it will.

[melosu58]

I definitely agree with Kurt as smaller frequent PWC`s is better. Here is a good article on QT care.