> pH: 8.0 to 8.2 > years? Tap water is pH 7. Any idea what is raising the pH? Chuck- I have no idea why the pH is so high. I cranked-up the CO2 to 130 bubbles per minute (on my moderately-planted 75 gallon tank). The pH dropped to 7.4. However, this seems like a lot of CO2 for a small tank. Any thoughts? Tom