i have an aquarium that has been running about a month and i cant seem to get the ph level to balance out. i'll test it and it will be at 8.8 so i'll either change out 2 gallons with 2 of bottled spring water or i'll drop a correct ph tab in and it usually drops to 6.8 or 7.0 but within 12hrs it is right back up to 8.8. i bought a brand new multi stage filtration system and it still does the same thing. do you have any suggestions? please!!