Struggling to get phosphate down

jmp21677 · Apr 30, 2022

I have a 50ish gallon cube. Mixed with a few lps and several small sps colony sized frags. I'm struggling to get my po4 down. It's been at 0.25-0.33 for several weeks. Swapped RO filters, no reduction. I've been running small amounts of rowaphos in a reactor and I'm not seeing that help either? Could I be running the water through the reactor to quickly? I followed the rowa calculator and it's a very small amount they recommend for the reactor.

BanjoBandito · Apr 30, 2022

Is it stable? Why do you want to get it down? If you use lanthum to lower it will it climb back up?

Ghost25 · Apr 30, 2022

jmp21677 said:
I have a 50ish gallon cube. Mixed with a few lps and several small sps colony sized frags. I'm struggling to get my po4 down. It's been at 0.25-0.33 for several weeks. Swapped RO filters, no reduction. I've been running small amounts of rowaphos in a reactor and I'm not seeing that help either? Could I be running the water through the reactor to quickly? I followed the rowa calculator and it's a very small amount they recommend for the reactor.

Most live rock and sand is made of aragonite (calcium carbonate). The aragonite binds the phosphate from the water column. As you are removing the phosphate from the water the rock and sand are releasing the phosphate that they previously bound.

It is going to take some time to reduce your phosphate levels. I used lanthanum chloride, it works instantly, though you have to wait ~24hrs after dosing to get a good equilibrium reading.

vetteguy53081 · Apr 30, 2022

Assure your not getting false readings by taking a water sample to a trusted LFS that does Not use API test kits and see what readings they come up with.
Reducing feedings will help reduce as well as a teaspoon worth of GFO. Chemipure elite contains GFO but don’t do anything until you verify readings