aquarium gravel

Question
My tank is about 2 years old, is 20 gallons, I have 3 ornamental goldfish,my pump is the large Whisper, I change water every two weeks(25%), 1x a month, I do a thorough cleaning which includes the air tubes, the pump and all its pieces. All of my test numbers stay pretty good but I tend to have to really watch the nitrites because of the output from my fish.  Do I need new gravel, to bleach the gravel or what?  I'm reluctant to bleach it because of all the goodies that help my tank but I'm drawing blanks for what to do.  Thanks, Dana

Answer
Hi Dana;

You may be doing too vigorous a cleaning once a month on the filter and not enough on the gravel. It's not usually necessary nor a good idea to bleach it or replace it though. There is beneficial bacteria in the gravel that is still helping the filter to process waste. If it wasn't living in there, you would have ammonia and little or no nitrite. Change 25% of the water every week and vacuum the gravel but don't pull apart and clean out the filter too much. The beneficial bacteria lives on the filter pads but also on filter surfaces anywhere that water circulates. Every time we clean too much the beneficial bacteria we have killed has to repopulate and the result can be elevated nitrites and/or ammonia until the bacteria colonies recover. Rinse the filter pads every so often when they get plugged up instead of replacing them. If you rinse it off in a container of tank water and clear the crud so it runs more freely, it will still have most of the beneficial bacteria in it that keeps wastes processed. Filter pads should only be replaced when they won't rinse enough for water to flow anymore or they literally fall apart from age. I have some that have been in use for over 2 years. I rinse when they get plugged and put them back in. There is some very old but healthy bacteria in there!

If you find that it is actually nitrAte and not nitrIte that is elevated (a common mistake), do weekly 25% changes and gravel vacuuming as well as feeding less food. NitrAte is the end result of biological filtration. The more we feed our fish, the more waste they put out and the more nitrate the beneficial bacteria creates. Vacuum more aggressively until it comes up and the nitrate levels should start to go down.

Let me know if you need more help...

At Your Service;
Chris Robbins