I got a 10 gallon aquarium, i have it running, i used filtered water, and had it running for a few days. I checked the PH level and it read 7.6..or over, im sure its well over. I bought PH down and put the correct amont of drops in , wait 24 hours...check it and reads the same, i repeated this process for a week now and nothing has changed. I currently have no fish in it. I have 2 plastic Ortiments in it.