Ammonia Reading High after 98% water change

I'm not sure if I believe that the badges work, but Seachem does claims their ammonia alert badge works when cupramine is used. The op said he was using a badge.

 

I agree, great info!

 

I would agree also but my system does not let ammonia by, spectrapure system fairly new (3 months old)

 

Here's a question, how many fish do you have in your tank? And, how long has it been running?

 

This is a QT and the tank had 1 fish in it which did not make it, after the fish was gone I drained the 20g down to 5g. Then the tank sat for a week (cause I wasnt rushing to do anything) then I drained the tank down to <1g and added 15g of new water. The tank currently has 0 fish in it and reads high ammonia. It is bare bottom, the filter is not being run, and there IS a piece of sponge in it from a existing tank.

 

What is the ammonia level in the tank from where the sponge came from?

Was the same sponge in the tank when you treated the tank?

 

The sponge came from a 7 month old tank with a ammonia reading of 0. The sponge was cut in half and added to two qt tanks. so it was in there during treatment. Are you thinking that it stored cupramine causing the false high? Or that there is substantial bacterial die off from that sponge?

 

Definitely both. When I use treatments I always remove the filtration media.

 

I will assume this theory the cause but the other tank has sponge, same treatment. No ammonia spike to high levels

 

I can only assume that this sponge has more of the treatment in it. Since the tank is empty and the source water has 0 ammonia. If you remove the sponge and remove the ammonia filled water you should have 0 ammonia.