Brian wrote:
I have a large tank with a light fish load. My nitrates are around
10PPM. Do you need to do a water change with such low nitrates?

When I had a heavier load I would water change enough to keep nitrates
below 40ppm but since my load is lighter the levels of nitrate are
taking much longer to rise.

Brian

You should do water changes no matter what your nitrate levels are. You
could go with a 15% every week or maybe a 25% every 2 weeks.