Can’t lower phosphates

[reefyjoe]

Hi ,
My tank is around 16 month old . I, for the life of me, cannot seem to reduce my phosphate I test bi-monthly with Hanna testers and the result is always 0.9 which I believe is the tester maxing out.

All fish are okay however my corals seem to be struggling. I’ve had a full zoa garden seem to dissolve and also all pulsing xiena.

Over the past couple month I have fully cleaned out the sump . Vacuumed the sand and have had a Gfo reactor running which seems to be having no effect .
I have had another recent icp test done to confirm my Hanna result which was 0.805 mg/l for phosphate so I know the tester is reliable .

The tank is a Red Sea reefer 250.
Fish : 2 clown fish, 2x wrasse , 1 x fox face , 1 x filefish.
I dose all for reef daily and do 2 x 50 litre water changes a month.

Is there anything else I can try?

 

[Randy Holmes-Farley Verified Community Expert]

It is hard to lower phosphate that much. You may need to repeatedly replace the GFO if you go that route.

 

[Troylee]

I’d lower it slowly with phosphate E or something along those lines and then use gfo to keep it down…