**rkeehn547**

- #1

Hello, I’m wanting to do a 50% water change per week for my planted aquarium but I don’t know how much water to take out. I have a 20 gallon tank and when I took out 10 gallons of water last week my nitrates went from 30ppm to 10ppm which means I really took out 65-70% of the water(I’m assuming because of the gravel and decor in the tank taking up space). Is there any way I can figure out exactly how much water to take out to equal 50% of the water volume? Thanks