nitrate problems - nopox and phosguard ++ ?

Hey,

i recently had white spots in the tank and 50% of the fished died (i didnt find some of the fishes) now i have nitrate problems.

I have 30ppm nitrate and 0.01 ppm phosphate.

I currently use: 2l matrix, 1l de nitrate, matrix carbon, phosguard and purigen. Phosguard and purigen in a reactor.



I was wondering if i could use nopox to remove the nitrate? Or is it bad to combine two methods of removing nitrate and phosphate?

I want to start with dosing nopox...



I have lost 1x favites, 3x acropora and the rest of the sps have burnt tips and are brown...

Hammer, bubble and torch looks ok.



tank is about 90 gallon.

Last waterchange: 4 days ago (25%) it didnt affect the nitrate.