The fish tank i have crashed again. This time i didn't do anything abnormal. Just did regular water change once a week and topped off. I noticed my fish looked off so i went to check the water. The water had low ph. 6.0 or lower and so I checked the other parameters. The tank went into a cycle again after 5 weeks. The kh is 0. I did a water change, within 6hours it was zero again. I have no idea what happened or why. It's in a hard crash and my poor fish is in the middle of it. I'm not sure how to fix the issue. Buffering the ph/kh dip does nothing as it just reverts to 6.0/0 so fast I'm afraid I may lose my fish. What would cause the kh to dip that fast? I've heard that kh can send the ph and water into a cycle. What I mean by 0 is 1 drop and its yellow.