Nitrates at 50ppm and PH readings?

[ppht]

I am using an AC3 with PH probe . It is reading 8.58. So I broke out the test kit and here are my readings. PH shows different with chem kit.
PH 8.3 maybe 8.4
Nitrates 50ppm
Ammonia - 0
Nitrites .1
Alk - 1.9
Salt - 1.25

What do you recommend?

[Randy Holmes-Farley]

The pH is likely OK unless you are using a lot of limewater. You might recalibrate the pH probe with new fluid and see what it reads then.

I'd look to lower nitrate, and possibly measure phosphate. I prefer skimming and growing macroalgae to reduce nutrients, but there are many methods:


Phosphate and the Reef Aquarium
http://reefkeeping.com/issues/2006-09/rhf/index.php

Nitrate in the Reef Aquarium
http://www.advancedaquarist.com/issues/august2003/chem.htm

[ppht]

I use no Limewater and My sump has Bioballs. Do the Bioballs read high Nitrates?

[Randy Holmes-Farley]

Many things contribute to high nitrate, possibly including bioballs, and in general it simply indicates an imbalance of nitrogen additions over nitrogen exports.