High ammonia for an unknown reason, pls help!

[seefour5]

Hi, I have a Fluval Evo 5. The tank has been running for about 6-7 months now, absolutely no issues until now. I had a pike blenny and a elongate dottyback (too small of a tank and overstocked, I know, was planning on moving them to a 16 gallon) until both vanished one day. I pulled apart the rockwork and took out everything, but couldn't find a body anywhere and it doesn't smell of ammonia. However, I'm reading around .5-1 ppm ammonia which I obviously need to get down. I've done two 25% water changes since then, once cleaning the sand the second just pulling water, which has lowered my nitrite back to 0 but I'm still seeing the ammonia. Corals are doing fine, I have acros and montis that are fully extending and don't look at all angry. Any ideas to where this ammonia spike could be coming from, and could it be a false reading?? Thanks!

 

[Pickle_soup]

Hi, I have a Fluval Evo 5. The tank has been running for about 6-7 months now, absolutely no issues until now. I had a pike blenny and a elongate dottyback (too small of a tank and overstocked, I know, was planning on moving them to a 16 gallon) until both vanished one day. I pulled apart the rockwork and took out everything, but couldn't find a body anywhere and it doesn't smell of ammonia. However, I'm reading around .5-1 ppm ammonia which I obviously need to get down. I've done two 25% water changes since then, once cleaning the sand the second just pulling water, which has lowered my nitrite back to 0 but I'm still seeing the ammonia. Corals are doing fine, I have acros and montis that are fully extending and don't look at all angry. Any ideas to where this ammonia spike could be coming from, and could it be a false reading?? Thanks!

Some tests will always show some ammonia. Every time I used API I showed a minimum of .25-.5. You wouldn't be able to smell ammonia at those concentrations. I can see a spike after two fish died, but corals would show signs of stress first, they are more sensitive to bad water. Did the fish show any signs of distress? Nitrite should be at zero once the cycle is over, I don't even test for it once I get nitrates on a test.

 

[seefour5]

Some tests will always show some ammonia. Every time I used API I showed a minimum of .25-.5. You wouldn't be able to smell ammonia at those concentrations. I can see a spike after two fish died, but corals would show signs of stress first, they are more sensitive to bad water. Did the fish show any signs of distress? Nitrite should be at zero once the cycle is over, I don't even test for it once I get nitrates on a test.

no, none at all which is the confusing part! the dottyback was in and out of my rocks and then one day just didn't come out. The blenny was super active, came out immediately for feedings so not seeing it when I fed was a sign something went wrong. I had a very small decorator crab, about 2.5 inches across that I want to blame but cant imagine it would beat up both to the point of vanishing. the corals have showed absolutely no distress, in fact my frogspawn has been more open than it has in months since this happened.

 

[Pickle_soup]

no, none at all which is the confusing part! the dottyback was in and out of my rocks and then one day just didn't come out. The blenny was super active, came out immediately for feedings so not seeing it when I fed was a sign something went wrong. I had a very small decorator crab, about 2.5 inches across that I want to blame but cant imagine it would beat up both to the point of vanishing. the corals have showed absolutely no distress, in fact my frogspawn has been more open than it has in months since this happened.

When in doubt, it's crab's fault. He either killed them or ate their dead bodies. I refuse to put any crabs in my tanks that are bigger than hermit crabs.

 

[seefour5]

When in doubt, it's crab's fault. He either killed them or ate their dead bodies. I refuse to put any crabs in my tanks that are bigger than hermit crabs.

yup, thats where im at now. it's going back to my job tomorrow, and i dont plan on touching a crab bigger than a hermit for a long long time. i appreciate the help!