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View Full Version : How to Get Bound Phosphate Out?


ccradr
10/27/2008, 05:41 PM
once it is bound in your rocks...how do you get it out?

bertoni
10/27/2008, 10:50 PM
Some people keep chunks of live rock in the dark for months, doing water changes. That might help. A more drastic approach is to give the rock a dip in diluted muriatic acid to remove the surface layer. In practice, a good nutrient export system might do enough that the tank has no problems.

sdietz2469
10/28/2008, 12:23 AM
i have been told it an be "extracted" by doing a bleach dip. not sure if this works, and it would kill the rock, but thought i would post it.
shane

newclean
10/28/2008, 01:19 AM
What about raising the temperature? That usually works for increasing solubility of solids in water.

Randy Holmes-Farley
10/28/2008, 04:32 AM
Bleach will not be effective at removing bound inorganic phosphate, but it would kill everything and remove bound organic materials, which may themselves contain organic forms oh phosphate as are found in organism tissues.

I do not think that temperature is a useful plan either.

One gentle way to remove it is to just keep the rock in low phosphate water, like with heavy GFO use or other ways of reducing phosphate. That works in a living tank, but can be slow and/or expensive.

Acid rinses are fast and cheap, but kill everything.

Rock "cooking", which Jonathan mentions, allows bacterial processes to work and is slow and cheap, and permits some organisms to survive.

ccradr
10/28/2008, 06:25 AM
What about dosing the tank with Vodka prodibio? Does that help to get the bound phosphate out?

kaskiles
10/28/2008, 06:29 AM
I just received some dry Fiji Eco Rox, and was planning to pseudo cook it with GAC and GFO.

I'm going to load the rock into a 10 gallon tote, with some fresh IO salt water. Then run a Magnum HOT, filled with a bunch of GAC and some GFO, on it for a couple weeks.

I really doubt I can test anything on the tote water to be sure I'm doing anything, but was thinking I might notice some change in the surface appearance (not all of the surfaces are bright white).

HighlandReefer
10/28/2008, 06:33 AM
All the different methods for exporting phosphates will help:
1) Fuge with dsb & macro algae. Plus dosing iron for macroalgae.
2) using RODI water.
3) GFO/GAC in a reactor.
4) dosing carbon sources.
5) Proper techniques for feeding your fish.
6) Proper skimming techniques.
7) Proper bioload in your tank (number of fish)
8) Proper water changes.

ccradr
10/28/2008, 06:43 AM
sow will the bound phosphate leach out of the rock once the water column is clear, and then its removed by one of the above methods?

Randy Holmes-Farley
10/28/2008, 06:54 AM
Yes. Inorganic phosphate that is bound to calcium carbonate is in some equilibrium with dissolved inorganic phosphate. So if you deplete the solution phosphate with any method (including bacterial growth), then you can potentially strip the rock and sand of inorganic phosphate.

Bound organics such as dead organism tissue, if there is any significant amount of that, will not be directly impacted by solution inorganic phosphate levels.

ccradr
10/28/2008, 06:57 AM
Thanks Randy, Highland and Bertoni!!

Randy Holmes-Farley
10/28/2008, 08:28 AM
:thumbsup:

Good luck. :)

tmz
10/29/2008, 01:06 AM
Nice thread very clear.

dngspot
10/29/2008, 09:22 AM
I agree this is a very nice thread and made very clear.
I also believe it has the ability to help a bunch of people.

dendro982
11/05/2008, 08:56 PM
Are liquid phosphate removers (presumable lanthanum based) like Brightwell Phosphat-E, acceptable for this task or they have some downsides?

My collection of the sun corals has to be fed, and large amount of food is added. Once white dead parts of skeletons became green. Granular phosphate remover, that works well for lower bioload, seems adsorbs added phosphates slower than they are added. Even with working skimmer and weekly water changes.

I tried liquid phosphate remover, after single dose in two days skeletons became much lighter.

Unfortunately, skimmer doesn't removes bound phosphate, and I have to rely on water changes.

bertoni
11/05/2008, 10:02 PM
The liquid phosphate removers work on phosphate in the water column. They probably won't do much directly for phosphate bound to live rock. They also have side effects, and leave the precipitate you've noticed, so I stick with GFO media.

Randy Holmes-Farley
11/06/2008, 05:00 AM
It will function as one of the ways of removing phosphate from the water that in turn may allow phosphate to come off the rock. It wouldn't be my favorite method due to the loose lanthanum particulates that you'll have to remove, but it could work.

dendro982
11/06/2008, 06:12 AM
So true, thank you both.

Randy Holmes-Farley
11/06/2008, 06:05 PM
:thumbsup:

Happy Reefing. :)

dendro982
11/07/2008, 06:22 AM
If I may, one follow-up question:
I used drastic measures for removing both: aiptasia and phosphate from the rock, repeated applicatons of the large amounts of the boiling water, scrubbing, soaking for 1 hr in the weak acid (1g of the white vinegar in 3g water), scrubbing and washing again, drying, exposing to near 0C temperatures.

As expected, the rock is dead, but still is green. How this dead microalgae can be removed?

I would expect, that bleach will go far deep in the pores and will not be fully neutralized by chlorine remover. Peroxide is too expensive, for 40+ Lb of rock.

This what was on rock long before cleaning:
http://i53.photobucket.com/albums/g78/dendro982/Some%20of%20the%20tanks/Problems/Jun20_08aftShellfD.jpg
My guess will be that this is result of the phosphates, accumulated in the rock, even with phosphate remover in the sump.

Randy Holmes-Farley
11/07/2008, 01:29 PM
Bleach will probably work best. Folks have bleached rock and reused it after adequate washing.

dendro982
11/08/2008, 07:08 AM
What bleach dilution to use? How many water changes will be adequate (roughly), each with chlorine remover, or first only?

Randy Holmes-Farley
11/08/2008, 07:11 AM
I'm not sure, It probably depends on the rock porosity and the time you wait with each change. More time will allow more bleach to get out.

dendro982
11/08/2008, 07:11 AM
Thank you! Will do that.

Randy Holmes-Farley
11/08/2008, 09:40 AM
:thumbsup:

You can get a relatively inexpensive chlorine kit to test the soak water to see if anything is still coming off. :)

Jandree22
11/08/2008, 12:07 PM
What does 'GFO' stand for?

HighlandReefer
11/08/2008, 12:21 PM
granular ferric oxide

Randy Holmes-Farley
11/08/2008, 12:31 PM
I give more info on GO here:

Iron Oxide Hydroxide (GFO) Phosphate Binders
http://reefkeeping.com/issues/2004-11/rhf/index.htm

Jandree22
11/08/2008, 05:10 PM
cool, thanks for the link. :thumbsup:

Randy Holmes-Farley
11/08/2008, 07:13 PM
You're welcome.

Happy Reefing. :)