OK...so I am ready to change the water in my 30 gal tank. I have 15 gallons that have been treated with Amquel Plus and with an air stone that has been sitting out for 48 hours...but the pH is still 8.4!!!! And my tanks pH is a perfect 7.4. What should I do? It has been a week and I think it is time to chage the water!!!!
Thanks guys for the help!!!

You can try using a pH product like "proper ph 7.5" to set the ph of your prepared water to the desired level.