Ummmm Yep, Prime is quite pungent to be polite about and to be crass it reminds me of boiled eggs and beer farts! Luckily, I only use it on an "as needed" basis.(lol)
Your ammonia of .5 worries me as that is too high and needs to be down around .25 at maximum.
I don't feel that 20% water changes are ever enough and should be no less 1/3 of the tank. Also your Nitrates of 80 is also in the very beginning of the toxic range and should not be that high with plants in the tank. I would do 50% changes everyday until the reading stabilizes. Any chance you are switching the nitrate/nitrite readings?
I would not be too concerned over the pH until you can get everything else under control first. You can be chasing your tail trying to get the pH where you want it without taking care of the basics first.
Your ammonia of .5 worries me as that is too high and needs to be down around .25 at maximum.
I don't feel that 20% water changes are ever enough and should be no less 1/3 of the tank. Also your Nitrates of 80 is also in the very beginning of the toxic range and should not be that high with plants in the tank. I would do 50% changes everyday until the reading stabilizes. Any chance you are switching the nitrate/nitrite readings?
I would not be too concerned over the pH until you can get everything else under control first. You can be chasing your tail trying to get the pH where you want it without taking care of the basics first.