*All water hardness parameters will be referred to in German degrees (dGH and dKH)...
Group! I've come up against a strange situation with my water throughout the last several weeks (refer to my previous list postings about reverse osmosis to get more context). Indeed, throughout the battle waged against the local water supply, for my biggest tank I've come up against a situation I can't explain, or correct for that matter... _The short version:_ ammonia: 0 nitrates: ~15ppm nitrite: 0 GH: 12 (easily controlled upward or downward) *pH: 8.4 kH: 2 to 3* _The Long version:_ I can't understand that. With a pH that high, the KH should be high, right? Wouldn't that be what you'd expect? Right out of the 55 gallon drum collection barrel I put the fresh RO water into 5 gallon jugs and treat the water with buffers and remineralize it, mix it all up, and let it be for about 5 days. At that point I measure it and pH is at a perfect 7, KH is 6, GH is dependent on how much remineralizing additive I've used. I had been doing semi-weekly 20% water changes with this "purefect" water for about 2 weeks give or take. It added up to about 4 water changes. The high pH<=>low KH condition persisted *in* the tank after the tank water was tested. Finally I decided I'd risk a 60% water change using the "purefect" water source. I reasoned that the fish had been exposed sufficiently to the new water that the change would be minimal, and I performed the change over a 4 hour period. Then I waited... for 2 hours, and tested the tank water. pH was 7.1, kH was 3, and GH was 12 (I'm going to be reducing that slowly downward into the discus-friendly range). Finally I waited until the next afternoon and tested the water again. pH was 7.4 and kH was 2. GAAAA! At this point I started getting concerned about pH crashes and poised some questions to the group and at other online places of aquatic community. My responses here on TFA FARRR outshined the horrifically-transparent anecdotal BS. I was comforted by what I learned in the thread because my tank is heavily planted. I also took heart because the tank remains at a steady kH of 2 now. _The Conclusion:_ I desire more KH and a lower pH. What I'm seeing is not what I expected. _The Questions:_ What could explain this situation, and how could I attain my goal of pH 7, KH 6? ~nc
