How to strip phosphate out of a dry rock pre setup

[Dr. Reef]

As the title says,
How can we strip phosphate out of a dry rock before putting it in the main tank?

People use acid, people use Lanthanum chloride and some simply cure/seed the rock but I have not been able to find a step by step guide to simply strip phosphate.

I know phosphate levels in rock or in water will always try to match itself whichever is greater so by simply placing rock in some water and using gfo or LC can start bringing phos out of rock into water. As you keep stripping water, phosphate levels from rock will reduce and eventually leach out completely.

How can we do this? Simply use rodi water?
Or saltwater?
What temp do we run?
Use power head or skimmer?

If one uses acid bath, it will only strip the top surface and not the internal locked in phosphate.

If you you LC, it will eventually get rid of all the phosphate out of the rock but how long?
Depending of amount of rock and amount of phos locked in can take upto weeks to years.

Any quicker more efficient solution?
Anyone with more details like to chime in
#reefsquad

 

[homer1475]

I used LC with my dry pukani.

What I did was follow a post on RC. Basically no heat and just RO/DI. I dosed LC every day, cleaning up the precip(the precip is the LC binding to the phosphates)daily.

It took me about 2 weeks to rid about 60 pounds of dry pukani.

 

[Dr. Reef]

Ok great, thank you for the post.
Did you use any water movement in the container?
A power head or submersible pump etc?
How did you remove the residue left behind using LC.

Do you wash the rock with tap water or power wash after treatment is done over with?

Btw I have been using LC in my main tank over 7 yrs now and I have 3 stage filtering process I use to clear the residue.

 

[NY_Caveman]

I used LC with my dry pukani.

What I did was follow a post on RC. Basically no heat and just RO/DI. I dosed LC every day, cleaning up the precip(the precip is the LC binding to the phosphates)daily.

It took me about 2 weeks to rid about 60 pounds of dry pukani.

That is quick.

 

[homer1475]

Yes I used some agitation in the water. I had a spare submersible pump I placed in the bottom just to keep the water moving. Would probablt have used a PH if I had a spare one at the time.

I would skim the precip off with a fine mesh net, then every couple days replace all the water in the barrel. I only had 60# of rock so it was just one large brute can.

 

[Dr. Reef]

I know right, it took me 2 yrs to strip all the phosphate out of 200 lbs of pukanii in my main tank with several diluted LC dosing daily but in a treatment container we can overdose LC. I like to see the results on that.

 

[homer1475]

Ok as a caveat, I obviously did not rid the rock of ALL the PO4(even though my hanna ULR read 0 for several days). I had subsequent issues with GHA that ended with me tearing the tank down and acid washing the rock(had other issues as well that ended up with tearing down the tank and replacing the rock).

I ended up giving it away to a friend I'm mentoring. After acid washing it, he has had 0 issues with the rock.

 

[NY_Caveman]

• I soak in RO/DI for a couple of days and take a PO4 reading.
• If high (over 1 ppm) I bleach for two weeks in RO/DI. No heat, no flow.
• Then use RO/DI for the soaking. No LC. No heat. Yes on flow. Several 75% water changes.
• Once it plateaus, if I am happy (PO4<0.2), I start cycling in a bucket of saltwater with heat and flow.

That all could take 2-3 months. I have used LC a bit recently and find I would use it in this process in the future.

EDIT: I should add my current system used about 25% dry rock to 75% live rock.

 

[Dr. Reef]

I have heard reefsaver rock is not so bad on locked in phosphate. any thoughts?

 

[lapin]

I have heard reefsaver rock is not so bad on locked in phosphate. any thoughts?

Are you taking about ?
https://www.bulkreefsupply.com/marco-reef-saver-dry-aquarium-live-rock.html
Reef Saver Aquarium Dry Live Rock
Dry and Live Rock is what confuses people. It is not live. It once was a million years ago. Let me know if this is what you mean. I have experience with the Dry Marco stuff. This is what a ton of it looks like.
Lots in the tubs with a 1/3 truck load to spare

 

[Dr. Reef]

Yes that's exactly I have 300# of it.
Its BRS dry reef saver rock.

 

[Reefahholic]

I’ve done this several times using a Vat/Stock Tank.

Start with a dose of 20ml SeaKlear commercial. Dose into a large 5-10 micron filter sock. This prevents any flocculant from building up on or in the rocks. If the rock is really dirty run a skimmer and do water changes as needed. Ramp the dose up as needed (30,40,50ml, etc). Dose until you’re Phosphate is reading 0 for 1-2 weeks using a Hanna ULR. Once you’re sure it’s zero and staying zero...you’re done. I’d do a Vinegar or bleach bath to make sure there’s no flocculant on the rock. You can never be too safe!

The great thing about doing this out of the tank is that you can absolutely NUKE the rocks without the presents of fish and corals.





BTW... the last time I cured Marco rock, I found it to be very clean. The process was quick. BRS Pukani is a different story!

 

[lapin]

I bought a literal ton from Marco in big pieces. I rinsed it off with a garden hose to get some dust off. I threw some in those 100 gallon tubs with power heads, heaters and salt water. After 3 days I did a P04 test. It showed very little on my Hanna ultra low meter. I then cycled it with bacteria, ammonia, dead shrimp, rotifer change out water. I tested again for Po4 at 1 week and 3 weeks. Still none was leeching. I cycled it for 2 months before putting it in my tank. It does have a lot of dust that comes off it. I had to rinse it again before placing it in my tank. It drills pretty easy and you can chisel it. A lot easier when wet than dry. I had extra, Cycled that too and sold some off. People said it had no Po4 when they tested it either.

 

[jda]

I did a phosphate experiment and Dr. Holmes-Farley helped with some variables.

Temperature matters... 78-80 will unbind faster than cooler temps. Salinity will matter too... get it up to 1.026 to 1.028 and you will have better results. Aeration and gas exchange played some role, so a skimmer that you can set in there will help too.

It can take weeks for the phosphate to make it's way out from some of the inner crevices and holes... this can be impeded by organics/gunk, so power washing might be good. Even with clean rock that was very porous, it took about 48 hours for the water to stabilize with the P release.

I also agree that LC would work best with hither concentrations. Once you get to 30-40 ppb, then you need some alum oxide or GFO to get the rest since LC is not really efficeint with low numbers since there is not an abundance in the water column.

 

[Reefahholic]

Forgot to mention that I used RODI water, but you can use SW too. I didn’t use heat, but you can heat if you like. Mine was treated with LaCI3 to specifically remove any potential bound phosphate and prevent possible leeching later on. If the rock has a lot of visible organic matter, I’d use saltwater so it can be skimmed off or bleach the rock before you dose the LaCI3. Bleach would be my preferred weapon of choice against organics.


After this is complete, this would be the time to use SW, heat, and heavy flow to actually cycle the rock. You can also use a bacterial supplement like Zeo Bak. If you don’t want to cycle in the vat... simply cycle in the tank.

The reason why I prefer not to use SW while I’m treating with LaCI3 is because sometimes large water changes are needed which can get expensive unless you use “OSW” water from a DT. If you think about it logically, SW is not needed while treating the rock. RO works just fine. I wouldn’t use tap because obviously you don’t want to introduce any TDS into the rock.

 

[Reefahholic]

55/G stock tank from Tractor Supply. Not sure if you have this store near you. Perfect height for a skimmer. If you use a large vat you can put the skimmer on top of a bucket.

 

[Dr. Reef]

I have large laundry totes probably about same size or maybe a little larger 55 gal each.
I have 3 of them.
I'll be using them.

 

[Eagle_Steve]

TSC stock tank. So many uses..... Love those things.

Also, these tanks do not leach anything from my experience. I use them for water troughs for my goats and mini horses. I have also cured tons of rock in them and even the 5-6 year old ones still are holding up like a champ.

 

[Reefahholic]

This would definitely need a skimmer!

 

[Reefahholic]

And these 40/lb Pukani boulders!