So I set up this 28 gal aquarium on Feb 5th. It has filtered, softened well water in it so the Ph is always pretty high, but I don't have problems with chlorine or other conditioning issues. I've been testing it regularly and other than high Ph - I had always had practically no nitrates or nitrites. I slowly added fish over time - everything was great. I went out of town last week and had a house sitter. I came home to cloudy nasty looking water. I assumed that she overfed. I tested and my nitrates and nitrites were both really high and in the danger zone on my testing strips. I did a 30% water change (my fish were looking stressed out and so I didn't want to do more.) The cloudiness resolved. That was Sunday. I tested today and I STILL had high on both so I did another water change of almost 50% because one of my angels was looking really iffy. I thought I needed to take a chance that this change would help or lose her. (I don't know if that was right or wrong.) The readings came down now and she looks better. My readings are still: Nitrate 50 ppm Nitrite 4.0 ppm The rest of the testing strip just shows that I am using softened well water so high Ph and no chlorine, etc. I also changed my filter even though my existing one was only about 2 weeks old. It was pretty yucky. What else should I do?