How to reduce phosphates of cycling rock

[Hotelbravo]

I have been acquiring dry rock for several months preparing myself to completely redo my 180 aquascape. I have pulsing xenia and pink and gold palys smothering all my rock and I want to remove all of that rock and start over.
I have made 3 large structures with the dry rock and reef cement that I will be using to replace my tank's rock with.
The rock is has been cycling in a 100 gallon Rubbermaid trough for over a month now and the phosphates keep going to 2.50 on the Hannah phosphate checker. I think 2.50 is the max that test can see so I'm sure it's well above 2.50.. I do water changes once a week of 100%. And the ammonia, nitrites, and nitrates have all stabilized to 0. Can't lower the phosphates though.

Any tips?

 

[Hotelbravo]

EDIT: not sure why it's posting the same picture twice. And I can't delete the second one.

 

[Randy Holmes-Farley]

100% water changes are not the best way to export phosphate in such a setting since it does not drop phosphate to zero due to large amounts bound to the calcium carbonate surfaces of the rock that come off as soon as the level is dropped when new water is added.

Many people use lanthanum chloride for this purpose. It keeps phosphate low by continually binding it up. Then you can mostly rinse the lanthanum away when you are done.

 

[Chitown tom]

I am a huge fan of lanthanum chloride. I prepared my new marco rocks in a garbage can prior to placing in my new DT. I checked the rock daily with an ultra low hanna checker. I kept adding a splash of LC daily until I was at 0.00. I then left it for a couple of days and checked again. Still at 0.00 I did a 100% water change, let it sit with a power head for a few days, another wc, sat for a few days again then went into the DT and I kicked off the cycle.

 

[Hotelbravo]

Thank you both for the lanthanum chloride suggestion. Do you have any instructions listed somewhere on a forum to show how much of this I use?

 

[Hotelbravo]

just stumbled on this. Is this still your stance on the product? @Randy Holmes-Farley

 

[Randy Holmes-Farley]

Yes, I'm still "not a fan of lanthanum" for use in a reef tank. But for cycling rock you can rinse it away.

 

[Hotelbravo]

How much and how often do I add it?

 

[Randyp79]

I have been acquiring dry rock for several months preparing myself to completely redo my 180 aquascape. I have pulsing xenia and pink and gold palys smothering all my rock and I want to remove all of that rock and start over.
I have made 3 large structures with the dry rock and reef cement that I will be using to replace my tank's rock with.
The rock is has been cycling in a 100 gallon Rubbermaid trough for over a month now and the phosphates keep going to 2.50 on the Hannah phosphate checker. I think 2.50 is the max that test can see so I'm sure it's well above 2.50.. I do water changes once a week of 100%. And the ammonia, nitrites, and nitrates have all stabilized to 0. Can't lower the phosphates though.

Any tips?

Lanthanum Chloride will drop the phosphates immediately. I used a product called Sea Klear for pools. Cheap and effective...

 

[Holy_makerel]

Lanthanum Chloride will drop the phosphates immediately. I used a product called Sea Klear for pools. Cheap and effective...

Exactly what i have. Perfect for curing out rock. Speaking of that i need to test my curing bin tonight

 

[Hotelbravo]

@Randy Holmes-Farley thanks for the tips

7 days ago I put the Lanthanum Chloride in the rock bin. The water tested 1.83 phosphates (crazy high) before the lanthanum chloride. Today I tested the water and it came out to 0.13 phosphates...
I removed the water and rock and thoroughly rinsed the rock and container it was in. Then filled it back up with clean and new saltwater.
How long should I continue testing the water to make sure phosphates do not continue leaching out? I would love to add the rock to my display on Sunday but I can wait if needed.

 

[Mombo]

I didn't think salt water was required for curing rock. Any advantage to it?

 

[Hotelbravo]

If you do not use saltwater you are not building any bacteria or any biological colonies.

If you use fresh to cure rock. All of the biological colonies formed during this curing process will die when added to saltwater.. and then the die off will just add to undesirable nutrient levels.
Just my 2¢

 

[Mombo]

Ah! Thanks. I didn't think of that. Does the temp of the water it's curing in affect it as well?

 

[Idoc]

Ah! Thanks. I didn't think of that. Does the temp of the water it's curing in affect it as well?

The warmer the water, usually the faster the breakdown of the organics in the rock. I cured some Pukani in freshwater for 6 weeks at around 84 degrees to get done of the organic debris to breakdown. I used freshwater since I planned to remove the rock to completely dry out again in order to work on some dry aquascaping ideas...i didn't intend to build a bacterial colony at that time.

 

[Hotelbravo]

I did the complete opposite. I took dry rock and build an aquascape then started the curing process

 

[domination2580]

Lanthanum Chloride will drop the phosphates immediately. I used a product called Sea Klear for pools. Cheap and effective...

Any certain sea klear? Anything special to look for ?

 

[HolisticBear]

Any certain sea klear? Anything special to look for ?

I bought the wrong Sea Klear, so be careful. Some is pure LC, but some is a mix of LC and other chemicals. I just disposed of it and used Brightwell's version at BRS. I have a snall enough water volume that the $20 Brightwell is more than I'd ever need.