What worries me is the nitrite. You should look for "0".
If this is not a new tank, you need to add buffer to up the alkalinity, which will boost the pH a bit too. But the most important thing is to get nitrite undetectable.
I just did a 15 gallon water change and mixxed up another batch for tuesday. This tank has been up for about 4 years and I have never had a problem. till yesterday I put in a couple of them little red star fish and they both melted. I think I should have drip lined them but I floted the bags putting in a little of my tank water over about a 4 hour period then put them in. Did the low ph and alkalinity melt them or was it the nitrite?. I have had a fiji sand sifting star in there for about 3 years and he is still fine. O yea its a 55 with 60lb plenem sand bed 35-40lbs live rock.
