What could cause such a massive ammonia spike?

[Nicky]

Hi guys,

We just got back from our honeymoon to find that my poor stressed mother has had to deal with an ammonia spike in the tank while we were away. Biggest one I've ever seen, the reading on the test kit goes up to 8 and even after a 50% w/c the reading still sits at 8...
Thankfully she went to the lfs with a water sample, they tested at the following:

Ammonia - 8
Nitrites & Nitrates both at zero
PH at 7.6 (usually this sits at 6.5)

So it would seem that we've had a total shutdown of the bio filter somehow. Is there anything other than a power-outage that could cause this??

For the 3 weeks that we were away, she was doing 50% w/c every 2nd day, using Ammo Lock, Prime & some Bio Booster also. Thank goodness, I know she probably should have taken them out straight away, but if she hadn't done at least what she did, we'd definitely have lost our fish by now.
Obviously over this time our fish have become very stressed, I've taken them out and put them in our 4ft tank in the shed which has housed our solitary goldfish for the past 3 months or so...
Fingers crossed that they make it though.

So what to do now? I guess I need to start from scratch and try to cycle the tank again...
Also, should this ammonia spike have affected our plants? because they are looking better than ever...

Fingers crossed for my dear fishies...

Any advice or whatever would be greatly appreciated guys.

[ILLUSN]

you've had a filter failure, something has knocked out your filtration bacteria, they only thing you can do is re-cycle the tank again.

extreme over feeding can cause that as can a dead fish floating in the system (NH3 gets too high and the other species of bacteria die out)

the ammonia wont hurt the plants, they prefer ammonia as a nitrogen source over both NO2 and NO3.

good luck with them, keep us posted as to how they go.

[JoeDiscus85]

did you get your ammonia under control?