Phosphate heavy rock... save or toss?

Nburg's Reef · Dec 15, 2018

I have a huge shelf piece that is awesome, but I pulled it because it was a red turf algae magnet. I threw it outside over the winter, bleached it, and soaked for months. Cured it and threw it in a new 15g frag display... tan it for 2 weeks to to stabalize in the tank and tested... 0.32 ppm phosphate. Nothing added and all the water was fresh saltwater after 3 weeks.

So with that much phosphate coming from the rock... is it worth trying to leach the PO4 out with acid or just scrap it? I broke an end off to make a nice layered rack look and it was greenish inside the rock.

roberthu526 · Dec 15, 2018

0.32 is not that bad at all. You can either dose Lanthanum chloride to remove the phosphate and run skimmer to skim the residue out. Or you can dose nitrate and bacteria to use the skimmer to skim the dead bacteria out.

TexasReefer82 · Dec 15, 2018

I have an sps dominant reef and I dose both phosphate and nitrate to maintain their levels sure to consumption by corals. I'm currently at about 0.1 phosphate and I think that's just fine.

I'd use the rock and let's the phosphate leach as it will. The corals will use it.

Mark Waltermire · Dec 15, 2018

I personally used LaCL3 whenever I was curing my dry rock. I let it sit in a 10 gallon trash can for a few days and then started dripping LaCl3 into the bucket and a white predicate formed. I kept on adding it until predicate stopped being formed, then I dumped out the bucket of water and repeated until nothing no predicate was being formed, which was about a couple of weeks.

Mark Waltermire · Dec 15, 2018

It's one thing though when you're adding phosphate and nitrate to an established tank with SPS everywhere and coralline covering all of the rocks, versus setting up a new tank where everything is unstable.

TexasReefer82 · Dec 15, 2018

Algae will grow whether your phosphates are zero or 0.3. A new tank will always go through an ugly phase.

Why not just run gfo in a reactor?

Nburg's Reef · Dec 15, 2018

TexasReefer82 said:
Algae will grow whether your phosphates are zero or 0.3. A new tank will always go through an ugly phase.

Why not just run gfo in a reactor?

I'm not worried about an ugly phase, the reason I originally pulled it was it grew red turf algae like a grass lawn while all other rock was fine in a mature tank. And I disagree about 0.32 ppm being fine. I shoot for 0.03 and when PO4 is 0.32 and nitrates are zero, that can lead to problems. high phosphates work for some people depending on other factors, but not for most. I'm wondering if treating it will pull the PO4 out or not worth the effort for 2 pieces of dry rock. I shoot for a simple as possible so I don't like adding more and more equipment like a GFO reactor to keep things in check.