Hey everyone, I have a 20 gallon planted aquarium which is heavily stocked and I’m wondering when I should do water changes and how much water I should be changing. I did an experiment and found that my tank produces 20ppm nitrate per week. I’m trying to avoid having over 40ppm nitrate in the tank at any time. Should I do a water change once or twice a week? And how big of a water change? I’m also wondering how much nitrate I should have in my tank for optimal plant health/growth. Thanks!