How to lower high phosphate

[MollyDog]

The issue with high phosphate is that it binds to carbonate surfaces such as reef rock.

What that means is that when you remove it from the water it leaches back out of the rock giving the impression that it is bouncing back up again. That is why although nitrates are easily removed with water changes, the same is not true for phosphate.

To bring them down in a nano, I'd suggest an aluminium oxide based phosphate remover such as Phosguard.
It has the advantage that it does not need to be tumbled like GFO, and can just be placed into a bag in the water flow. Rinse well before placing into the tank.

You will find it will take quite a while to come down from 0.4ppm, however you do not want to go fast as rapid reduction can result in poor reactions from organisms in the tank.

I second a slow removal process. I dropped from 0.67 to 0.08 in two days with a 1/4 cup of high concentrate GFO in a 30g system and a week later everything is starting to loose color and retract. Slow is best!

Also are you using RODO water? My issue was I was using tap water and my source water was reading 0.9 after checking!

 

[Nman]

Update
Phosphate is reduced to 01 and stable.I took a chance with L chloride and it has payed off no effect to fish nems coral . I used Randys recipe to the letter and I have to say spot on no problems whatsoever . And this is on a nano34L

 

[Nman]

All still level at 01 today

 

[Nman]

Update Using L chloride to lower phosphate it has worked spot on using Randys recipe.No I’ll effect’s to fish / Anemones/ corals my phosphate is sat at 0.1 . I was a bit anxious about this stuff but worked great and did the job in a nano of 34L . This just my experience with L chloride and I rate it safe if dosed correctly and follow Randys recipe to the letter