Controlling Phosphate through rocks and sand

[ReefHunter006]

I am not sure if this has been discussed before. My search didn't turn up much, but I also wasn't sure what the best terms would be to search by. Regardless, has anyone evet tried to control phosphate through addition and removal of rocks and sand? The thought crossed my mind this afternoon after reading about how much phosphate sand and rock can bind up. If I were to take a tuberware of fresh sand, or new rock and put it into my sump would it remove phosphate in an effective manner that I could replace these items routinely to manage phosphate? Hopefully I explained that well enough.

 

[Dan_P]

Yes, PO4 adsorbs to aragonite. The sand in the bowl approach would not be very efficient unless you stirred the sand occassionally. Might cloud the water.

You can get a feel for how well this works by mixing sand with tank water and then measuring the PO4 level. Make sure to filter the water or let it settle over night before testing the water.

 

[Cory]

I dosed powdered calcium carbonate supplement and measured no change in po4 with hanna checker. Maybe it wasnt argonite?

 

[bam123]

Use e-phosphate. Make your life easy. Under dose by 50 or more percent and go slow.

 

[ReefHunter006]

Use e-phosphate. Make your life easy. Under dose by 50 or more percent and go slow.

I heard without a 5 micron filter sock it might hurt some fish due to the particulates. I have a bottle in cabinet, but scared to use it.

 

[bam123]

I heard without a 5 micron filter sock it might hurt some fish due to the particulates. I have a bottle in cabinet, but scared to use it.

Put it in the overflow (before the sock) and have a protein skimmer. It will be fine

 

[ReefHunter006]

Put it in the overflow (before the sock) and have a protein skimmer. It will be fine

Thanks for that! Just two more questions.

1. Do you still recommend this method when you have low levels of phosphate in the .1-.3 range!
2. Do you recommend this method with mandarins and tangs?

 

[bam123]

Yes and Yes. Dose very small and go slow. Can take more than a day for phosphates to come down and common to get error readings the next day. Dropping phosphate too fast will kill corals quickly. If PO4 borderline, I would just get an algae scrubber or refugium. Main thing is stability.

 

[Randy Holmes-Farley Verified Community Expert]

The rock and sand thing will work, yes, depending on how much you are planning to export that way. You need to be sure the rock or sand is not already bound with phosphate.

It will also export some organics and magnesium, although the latter is so high already you may not notice it.