In a message dated 5/19/98 9:45:33 AM EST, gomberg@wcf.com writes: << No tablets! Use peat. Just for the record, I just gave up on peat this week. After two months of running a box filter with sphagnum moss in my two 10 gallon tanks, all I had was brown water with a pH of 7.8. Hardness tested at 40 ppm, but I've come to the conclusion that my Wardley's hardness test kit only checks non-carbonate hardness. My water has a very high buffering capacity, which I think is from dissolved carbonate. Strange, dissolved CO2 will lower pH by forming carbonic acid (H2CO3), yet carbonate (CO3) in other ionic mixes makes it very hard to lower pH. I agree that peat usually works, and I have used it in the past with great success. Anyone out there know a good way for someone without the room or budget to invest in RO or DI to lower carbonates? Bob Dixon