New tank, 2nd cycle..?

[Andy_P]

So about 2 weeks ago I set up a new 20 gallon nano. Dosed Dr. Tim's ammonium nitrate to 2ppm and Dr. Tim's live nitrifying bacteria. Cycle went fine, checked last night and I was back down to 0-.25 per API test. Checked again tonight with a Red Sea kit just to be sure, ammonia is thru the roof. Grabbed the API kit just to see if it was really that off, and API also showed ammonia thru the roof. Like, 8.0 bad. What the heck happened? 0 fish, 1 astrea and 1 hermit added a few days ago, 0 lights. How on earth did it go from cycled to outright toxic overnight like that? I did do a massive water change after the cycle finished (like 90%), Tuesday, to try and get rid of some slime. Dosed Fritz 460 last night to help with the slime after the water change Tuesday. pH tonight was 7.6, so I'm assuming the water change dropped the pH and raised my toxic ammonia? I added another 2 oz bottle of Dr. Tim's tonight.. I haven't checked nitrates or nitrites today bc at that level of ammonia I assume it's just going to be a waste. I'm assuming another water change is about my only option, but how much should I do? 50%?

 

[Ron Reefman]

Quit dosing the chemicals and let the tank cycle on it's own.

 

[taricha]

there's very little that can cause nitrifiers to fail once they get rolling - but Oxygen is an absolute requirement. Slime + low pH suggests maybe a bacterial bloom that depleted all O2 and thus cycling can't proceed.
(sometimes if O2 is low and the bacterial bloom is rolling, it can even go backwards - NO3 reduced to NO2, and - rarely - even to ammonia)


Crank up aeration and no worries.

 

[Andy_P]

I figured out what the issue was.. Found out that my soon to be ex-wife was mad at me for waking up and dumped a 4oz bottle of ammonium chloride into the tank..