cant get ammonia to go down

[Just5398]

I'm trying to do a fishless cycle in a 20 gallon tank. The ammonia readings are in the 8 range with a liquid test kit. Today I did an 8 gallon water change and its still reading 8 so I added Ammonia Clear to see if I could get it to drop to a 4 or 5 but it's still an 8. I put in 2 tablets since each tablet covers 10 gallons. I also have 2 filters running and one has a carbon filter in it. Im adding stress zyme as well but I thought I read that it could give you a false ammonia reading by adding that. I thought with the AC tablets it would make it drop anyway.
What the heck is going on?!?!?!?

[candi]

How many days have you been cycling for?

[Rbishop]

Just drain the tank, fill it back up with prime as your conditioner. Dose SLOWLY back to 5 ppm. Do not over dose. High levels of ammonia will actually slow the cycle down even further. Stop adding all the other stuff.

[Just5398]

How many days have you been cycling for?

It's only been 4 days. I know I have a LONG way to go though.
I was afraid that the ammonia being so high would slow or prevent the cycle to get going.

Thanks.