I am newer to the betta in a way (my mom had them when I was a kid, but of course I wasn't very involved in upkeep, hehe) and had a question about water changes. My hubby & I each got a male betta. Each of our boys are in their own 10 gallon tank. Each have a waterfall filter (with the pump rate adjusted to its minimum) and an air pump with airstone for extra oxygen. We dechlorinated the water appropriately at setup, we regularly test the pH levels (which we maintain around 7.0), and we have a 5-in-1 dial thingy that stays in the tank to test the ammonia, nitrites, etc. and at all times the levels show safe. We don't have heaters for them at the moment (I know they need the warmth) but we do have thermometers and the temperature is consistently staying around 76-78 degrees. Next pay day we will be picking some of those up to install as I know we are merely maintaining those temps now because it is summertime & we don't have an AC. I read in the betta care - day 1 that it is recommended to change water every 4 days or so in a 10 gallon tank, but that didn't specify if that also pertained to tanks with filters. Anyhow, my question is this: with tanks setup as ours are, what should our water changing schedule be? Do we still stay on the desired schedule of all of the test results show a healthy environment?
Sorry to be long-winded... I just wanted to be certain to include the info.