Think Getting False Positive On Ammonia

Tank has been up and running almost two years. Had a columnaris outbreak a few months ago and have learned my lesson as far as quarantine. Treated tank and at the same time decided to switch to RO water.

Tested a few weeks ago was getting .5ppm ammonia, zero nitrites and 10ppm nitrates. Panicked. Added Fluval Cycle. No change for a few weeks. Added Dr. Tim's One and Only a week ago. No change. Water changes aren't bringing ammonia down either.

So, I'm thinking the ammonia is false. Not that the test is picking up bond ammonia from treating with Prime, but that it's actually shpwing ammoia that just isn't there.

What would cause this??

I use RO. Prime. Replenish. Neutral Regulator.
kh is 3 drops and gh is 4 drops. temp 79

help!!!! I have a seachem multitest on order

 

What are you using to test it? Are they strips because they can be very inaccurate

 

API liquid test

 

At first I thought the medication ad 100% water change killed the bbacteria, but I have no idea what's going on.

 

Ok, I got the Seachem Multitest and am getting ZERO free ammonia. That's good! Getting NH$ though. I know it can turn back into free ammonia and want to get rid of it. Why is my bacteria not getting rid of it??