High phosphates after acid bath

Reefnewb · Dec 8, 2017

Just like the title says... i have over 100ppm of phosphates after doing an acid bath on all of the rocks and restarting the whole system. The tank has only rock in it. Using a Hanna ULR tester. Shouldn’t the acid bath taken care of the phosphates? I have been running GFO the pasts 4 days and the phosphates are still over 100ppm

cumbeje · Dec 8, 2017

Your rocks are leaching phosphates. 100 ppm seems excessive though. You sure about those numbers?

Radman73 · Dec 8, 2017

Reefnewb said:
Just like the title says... i have over 100ppm of phosphates after doing an acid bath on all of the rocks and restarting the whole system. The tank has only rock in it. Using a Hanna ULR tester. Shouldn’t the acid bath taken care of the phosphates? I have been running GFO the pasts 4 days and the phosphates are still over 100ppm

Did you bleach the rocks first?

Randy Holmes-Farley · Dec 8, 2017

What sort of rock?

Reefnewb · Dec 8, 2017

Randy Holmes-Farley said:
What sort of rock?

I am not sure the type of most of the rock, because i got it from a local reefer. But some of it was BRS rock that i had in other tanks.

Radman73 said:
Did you bleach the rocks first?

I did not bleach the rocks first. I did not think you needed to before acid bath.

Reefnewb · Dec 8, 2017

Randy Holmes-Farley said:
What sort of rock?

Some pics if that helps at all

Cory · Dec 8, 2017

I wouldnt use gfo for this purpose. Id either use lanthanum chloride or dose iron pills. Gfo is too exspensive.

Charles4400 · Dec 8, 2017

Bleach was to kill and remove any organic matter in and on the rock. The acid bath was to remove the outer layer of the rock that may have absorbed phosphate.

Reefnewb · Dec 8, 2017

Cory said:
I wouldnt use gfo for this purpose. Id either use lanthanum chloride or dose iron pills. Gfo is too exspensive.

Yeah i agree with that. It’s all that i had on hand, but i thought that an acid bath would remove the phosphates. After being in saltwater for a couple weeks i tested the water and it was over 200+ppb after adding GFO i got it down to 99ppb but tested today and it’s back up to 120ppb

Radman73 · Dec 8, 2017

Reefnewb said:
I did not bleach the rocks first. I did not think you needed to before acid bath.

My understanding, which could be incorrect, is that the bleach is more effective at dissolving surface organics. So, dead stuff. The acid might eat away at it some but it likely wouldn't get all of it. The acid is used to dissolve 1-2mm of the outer shell and theoretically remove the phosphate from the rock that way.

Bleach first to dissolve surface organics, then acid bath to remove the outer layer of the rock which is the most likely to house phosphate.

Charles4400 · Dec 8, 2017

Are you using rodi water or tap? If tap, that might be the culprit.

Reefnewb · Dec 8, 2017

Charles4400 said:
Are you using rodi water or tap? If tap, that might be the culprit.

Yes using RODI water. 0tds using a handheld checker

Reefnewb · Dec 8, 2017

Radman73 said:
My understanding, which could be incorrect, is that the bleach is more effective at dissolving surface organics. So, dead stuff. The acid might eat away at it some but it likely wouldn't get all of it. The acid is used to dissolve 1-2mm of the outer shell and theoretically remove the phosphate from the rock that way.

Bleach first to dissolve surface organics, then acid bath to remove the outer layer of the rock which is the most likely to house phosphate.

Yeah i get that too, i just followed a step by step forum on here and nowhere did it say anything about bleaching first.

Pongo · Dec 8, 2017

Vinegar, bleach and acid all remove dead organics to some degree.

I would dose the tank with lanthanum chloride, then do close as you can 100% water change.
Recheck PO4, Rinse/repeat.
I would even fill the tank with RO/DI until you get the PO4 under control to save on the cost of salt.

Reefnewb · Dec 12, 2017

@Randy Holmes-Farley have you ever heard of phosphates coming off rocks after they have all been treated in acid?

blkhwkz · Dec 12, 2017

I did the muriatic acid bath on Pukani rock from BRS, then kept it in a Brute can and dosed lanthanum chloride every other day for 6-7 weeks. The first few days the phosphates were so high they couldn't even be read by the Hannah ULR. After the every other day of dosing lanthanum the numbers came way down. Had the rocks in my tank for about 16 months now and no phosphate issues. LC is going to be way more effective and cost effective than GFO until the numbers come down.

Reefnewb · Dec 12, 2017

blkhwkz said:
I did the muriatic acid bath on Pukani rock from BRS, then kept it in a Brute can and dosed lanthanum chloride every other day for 6-7 weeks. The first few days the phosphates were so high they couldn't even be read by the Hannah ULR. After the every other day of dosing lanthanum the numbers came way down. Had the rocks in my tank for about 16 months now and no phosphate issues. LC is going to be way more effective and cost effective than GFO until the numbers come down.

I have never done LC and to be honest kinda scared to dose it right into my tank....

Reefnewb · Dec 12, 2017

The only other thing i could think of is maybe something else is fueling the phosphates... i did paint the inside of my stand, but that was about a year ago and it has been dried and cured since.

saltyfilmfolks · Dec 12, 2017

Reefnewb said:
The only other thing i could think of is maybe something else is fueling the phosphates... i did paint the inside of my stand, but that was about a year ago and it has been dried and cured since.

You are correct. IMO.
And that number makes little sense.

Following along.