High nitrates and phosphates. Next steps

[saullman]

I have a Reefer 350 (91 gal total). I noticed my corals were not looking good. I took a water sample to my lfs (Top Shelf Aquatics) and they tested using the spin test. Results in pic. That was last week. Tonight I did some of my own testing. Most of my parameters looked good, however my phosphates were at .32 ppm and nitrates are almost off the chart (API) at 80 ppm. I know API is not the best test kit, but it's all I have. I am currently running rowaphos in the sump as of 4-5 days ago. Phosphates are slowly decreasing. Besides water changes which I know I have to do, how do I decrease my nitrates?

 

[PeterC99]

Refugium with chaeto!

 

[Elitecorals]

With water change you will decreases nitrate and phosphate, skimming wet and feed less. I would do 20% water change till your nutrients go down to a good range

 

[BlennyTime]

Red Sea makes a product called NO3: PO4-X that helps control both nitrates and phosphate. Would be another option.

 

[Randy Holmes-Farley Verified Community Expert]

With water change you will decreases nitrate and phosphate, skimming wet and feed less. I would do 20% water change till your nutrients go down to a good range

Water changes are not typically the best way to deal with elevated phosphate due to the large reservoir bound to rock and sand. Unlike nitrate, even a 100% water change may not take down phosphate very much.

There are plenty of good ways to reduce phosphate, but it also may not be critical as some great reef tanks have phosphate over 1 ppm.