I have a 55 gallon planted tank that I used Aqua Quartz Pool Filter Sand in. I had done research and found this substrate being highly recommended with no mention of this substrate raising pH (in fact, people praised it as being pH stable). My tap water is at approximately 7.2. Within a week, my pH is going slightly higher than the Color Card on my pH test kit which is 7.6. I do a 30% water change weekly and the pH comes back closer to tap water level. Last weekend I was away and missed my weekly water change. Came home from work yesterday to find a dead molly and the other fish highly stressed. I checked the pH and found it to be off the charts. The test kit was a deep blue. I did a 30% water change immediately and the aquarium water is almost back to tap water level again. Please help, I want my fish to have the best care!