Ammonia Test

Ammonia testing is crucial when starting up a tank. But what if the ammonia test, doesn't make sense? Can you help this forum member sort things out?

"Hi Everyone ... my name is Mike. I have a 35 hex. I've had this aquarium for many years and have had varied levels of success with keeping fish in it. I recently decided to break it down, clean it up and stock it with Angelfish. I found articles about 'fishless cycling' and decided to give it a try. I was amazed when it worked.

I bought six dime sized angels and one Pleco for my cycled tank. All was going well until one day I checked the water and found that the ammonia had spiked to about 8.0 PPM. I panicked and headed for the fish store. They said my problem was caused by my undergravel filter and suggested I buy a Rena cartridge filter and get rid of the undergravel. I followed their suggestion.

After 11 days I have a perfectly clear tank with an ammonia level of 8.0 PPM. Zero nitrites. pH 7.2. My fish seem fine. They are eating well and swimming around. They show no obvious signs of stress. I've been doing a 10% water change every three days but the water tests do not change. Do any of you have a suggestion for me? I'm baffled."