Ammonia spike

[Rooker]

Hello everyone, 

I am having issues with my ammonia. My ammonia has been spiked for about two weeks now and I can’t figure out why. I have done 10% water changes, 25% water changes and 50% water changes. I have also gone a couple of days without feeding.  I’ve been using prime, stress coat and fritzzyme 7. Nothing seems to be breaking it down. My 29 gallon tank is stocked with A hillstream loach, upside down catfish, 6 checkered board barbs, and 5 zebra danios. I have a HOB filter and a sponge filter. I also have 7 live plants. My tank has been established since 8/26/2020. My water levels are: 

ph 6.8 

ammonia is between 4.0 ppm-8.0 ppm

nitrite 0

nitrate 20

any suggestions would be greatly appreciated! Thank you! 

Sincerely,

Adam   
 

[Travis]

Is there any chance there is a deceased fish/snail etc. that may be hidden somewhere fouling the water? Are your live plants doing well or are they struggling? If you are doing water changes there has to be something that is producing a continuous spike in ammonia. Any major changes in your filter media that could have caused a loss of beneficial bacteria? Have you tested your tap water?

[Daniel]

I would test again. Ammonia at those levels could be lethal (but for your 6.8 pH). If your fish look good, could it be your ammonia test results are inaccurate?

It sounds like you have tested repeatedly. But if your test results are right, your nitrogen cycle is knackered.

[Rooker]

13 hours ago, Travis said:

Is there any chance there is a deceased fish/snail etc. that may be hidden somewhere fouling the water? Are your live plants doing well or are they struggling? If you are doing water changes there has to be something that is producing a continuous spike in ammonia. Any major changes in your filter media that could have caused a loss of beneficial bacteria? Have you tested your tap water?

I have tested my tap water and zero traces of ammonia in my tap water. I’ve also checked my tank for anything dead or decaying and Nothing is dead. I haven’t done any major changes to my filter media since I’ve had the tank. The only thing I’ve done was added a sponge filter. Some of my plants aren’t doing well but I have been removing the dead ones.