I agree with glitterfish. The stuff that removes ammonia can also prevent your tank from cycling properly (because it removes the ammonia from the cycle), need to be changed with some regularity & you can't use salt while it is in (which means that if your fish gets ill - you may cycle again. Probably not the time you want to be trying to do that.). What happens is that the ammonia remover eventually will re-release the ammonia back into the water (if it's not changed) & will re-release all at once all of the ammonia if you use it at the same time that you use salt.
I too think that Prime is a great water conditioner & a tremendous help during cycling .
While I was cycling, I tried to keep my ammonia & nitrite levels under 1.0 (still high I know, but if you knew the water changes that went into that...sheesh.) That's when I found Prime. You sound by your levels that you're well into the cycle. I think I'd just "tough it out" at this point.
If you want to, you could salt your tank to 1% to try to help your keep your fishies gills healthy during the nitrite phase of the cycle. (I use the 1 teaspoon per gallon rule = 1%). If you do choose to salt your tank - remember to only put back into your tank what you took out (ie if you do a 5 gal change, only put in 5 teaspoons. Do not salt for the entire tank volume everyday/every waterchange-salt is only removed with water changes & does not evaporate. You can quickly oversalt a tank that way.)
Good Luck & enjoy your fish!

Jenn