Large water changes input

[Reef Pilot]

I used to have very high nitrates (around 100 ppm). Did many frequent large water changes, and while they would bring the nitrates down a little temporarily, they would climb right back up in time for the next water change (2 weeks). I think my rocks and sand was super saturated with nitrate, and they would just leach out again.

Interestingly, the fish didn't seem to mind, and even my soft and some LPS corals were doing fine. But I did have a major algae problem, and had to clean the rocks and sand constantly.

Tried a few other things too, like a refugium full of chaeto, but that had no effect at all.

Finally used MB7 and got a bio-pellet reactor and that worked, although it took quite a few months. Now my tank has zero nitrates and near zero phosphates, and now have SPS growing well.

[ocean diver]

The high nitrates could be caused by the media in your canister filter, if you don't need the canister filter I would remove it or at least clean it out once a week.

Way back when I started I did remove 80% of the water and then filled it half way up then back down leaving about 20% then filling up again, but with in a week it was right back where it was.......so I would find the cause and try to reduce that source.