Fish tank STINKS (recent ammonia spike)

[mishfish]

Hello

Me again. If you see my other thread my daughter recently tipped a tub of fish flakes into a 34l tank causing a huge ammonia spike which cleared after 3 weeks. We lost 2 snails, 1 frog and 1 tetra in the process.

Last weekend we introduced 6 assassin snails as we have a severe pest snail problem (there’s literally hundreds). All snails are still alive and working away.

The last few days the tank has been stinking again. It smells of cats pee and you can actually smell it from downstairs (tank in sons bedroom). I did a search last night and found a dead Congo frog under the pump who has now been removed. I’ve done 2 x 25% water changes and added the API quick start to the water.

It still stinks. The surviving fish currently seem happy so I’ll keep up with daily partial changes but I’m wondering how long I need to ride this one out for? My poor son’s bedroom smells terrible- I actually asked him if he had had an accident and hidden the evidence in there.

So what can I do? Anything else I can buy?

Have you done a thorough gravel vacuum when you're doing the partial water changes? I would also reduce feeding right down to only once or twice a week - the creatures will cope.

Make sure there's lots of surface movement, add some extra air-stones if need be - and make sure the filter media isn't clogged. Don't replace the filter media though.