I have had my 55 Gallon Setup for at least 4 Months. all i have in it are 4 small Goldfish. I've had a MAJOR problem with PH. For all this time, i haven't been able to lower the PH to low enough to read on the kit i have. this means that it's 8.8+. In that time, i have Removed the large ROCK that was in there. I've tried PH Down to the point of using up two full bottles (Not all at once). I've done 33% Water Changes with Tap Water, Distilled Water and Well Water. No Change. Today i tested all 3 of those individually. The Well Water came in at about 8.4 PH, the Tap Water was 7.8 PH and the Distilled was 7.2 PH. I decided to bite the bullet and do a MAJOR water Change. I removed 40 Gallons of water from the Aquarium and Replaced with ALL DISTILLED water. This was about $45 worth of water. I turned everything back on and let it sit for about an hour. I tested the PH, and it's STILL OFF THE SCALE. The only thing in the tank other than water is the Gravel that i bought from Wal-Mart. I think it's Top Fin brand. What in the World do i have to do to get a decent PH?