Hey guys I have a 55 gallon tank setup with 2 filters running for a 60 gallon tank (just for cleaner water) and i want to know if its OK to do water changes once a week.. I have only 1 red oscar fish about 4" and hes a real messy eater and I want to keep the water very clean and spotless so he stays/grows healthy. I usually take about 20-25% of the water out just to get most of the crap out of the gravel and fill it back up with the garden hose and use some water conditioner. My heater is also set at 79-80 degrees just in case anyone is curious to know.


let me know !!

the best way of judging how often you need to change the water is by doing a nitrate test. Now assuming that you have a healthy biological filter and you don't have to worry about ammonia or nitrites then monitoring your nitrates will give you a good indication of how quickly the nitrate builds up in your water.

Check your nitrate levels at the end of one week. If they are still very low then a water change isn't necessarily needed. However, if your nitrate levels are unacceptable than a water change is definitely needed. The problem with keeping large fish in the small tanks is that it's virtually impossible to keep the water in good condition. That is why I try and drum home how important it is to have a large tank when keeping large fish.

if you want to keep your fish healthy then keep your nitrate levels under 40 ppm at all times. It's as simple as that