How often should i change the water in my red ear sliders tank?

The tank-40 gallons, I also have a good filter in there which i change the filter piece once a month. I have heard mixed things about changing the water. I am new to the turtle world so any information would help! thankssss.How often should i change the water in my red ear sliders tank?Change the water as needed, as long as you don't over feed the turtle you can change the water every other week. What are you feeding it? If you are feeding it feeder fish or meat you may have to change more often. If you are feeding it pellets then as long as you only feed a small amount each day then every other week for a tank change should be good

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