So my zenia has been dying off and my duncan looks very sad. I tested my tank water and the kh is around 50 mg/l and the ph is 8.6. It's a 30 gallon tank so I did a 5 gallon water change one day, then a 10 gallon change the next. No change to the kh, so I started to add Kent Marine Superbuffer-dkh. I tested my saltwater mix and its about 5o mg/l also. Is that normal? Is dkh effected by lights like ph or do I have bad salt?