PH and alkalinity levels

Question
My test strips indicate that my ph is 8.4, with an alkaline reading of 300. Hardness is 25, nitrite is zero and nitrate is 35. I have a five gallon freshwater tank and replace at least 1/4 - 1/3 of the water weekly. I have 2 tetras, one guppy and a small corydoras catfish, all whom apear healthy. Should I be concerned about the PH & alkaline levels? IF they are too high, what is the best way to adjust them? I do add a little sea salt to my tank with water changes. Thanks.

Answer
Hi Nancy;

If the fish are okay don't fight with the pH. As the system ages it will slowly drop unless it is caused by having shells, limestone or dolomite in the tank. These minerals leach into the water and continually raise the pH and hardness. Adjusting pH only causes fluctuations that are more harmful than one that doesn't seem 'right' for the species of fish you are keeping.

Is the water the same high pH and hardness out of the tap or just that high in the tank?

Followups Welcome

At Your Service;
Chris Robbins

Come on over and join us on the freshwater fish forum at About.com to get even more information too;
http://freshaquarium.about.com/od/questionsanswers/a/naavigateforum.htm

My member name is ChrisR62. See You There!