Will a "green sand" (ex. MetalTrap) filter remove sequestered iron?

[deanchat]

Hi Everyone,

I have some iron in my pool that I am trying to get rid of. It's not from the fill supply (probably from fertilizer and well-fed sprinklers spraying in the pool over time). Did a 30-40% drain and refill but I still have enough to mildly stain the liner when I raise the FC level. The stains start near my bottom returns (likely the heavily chlorinated water coming from the SWG stains those areas first), but then the whole pool gets a light brown tinge to it. I use Metal Magic (often) and it works but wears off pretty quickly. Luckily, when I get staining a bottle or two of Metal Magic will lift the stain (don't need AA treatment, which is a pain).

I want to run a separate utility pump to pull water from the pool, through a MetalTrap type (green sand) filter, and back into the pool. Does this type of filter work if the metal is sequestered or would I need to let the Metal Magic degrade before trying this?

Thanks,
Dean

 

[kimkats]

I am going to share a thread I found doing a search for green sand. There are many more but this is the first one I found BUT I did not read it. I will leave that up to you. Make sure to do more searches as well.

Manganese Greensand for Iron Removal

 

[basod]

What your wanting to try can be done. I built one last summer that uses time contact towers an air inductor and series filtration. With this process it requires time contact for oxidation to occur then filtration.
unlikely the greensand will filter sequestered iron, it will need to be oxidized most effectively with chlorine.
Theres no need to use a sump pump if you're handy with PVC it can be plumbed into the existing pump return.

Do a search for "sidestream" it'll bring you to that thread

 

[deanchat]

Thanks for the thread pointers, lots of good info in there. I'm still a bit unclear about whether a MetalTrap will filter sequestered iron. Obviously, when using the oxidize + mechanically filter approach the iron can't be sequestered but I believe the green sand type of filters also involve a chemically reactive component (ion exchange?) in the process. I know the CuLator is an ion exchange product and will supposedly work on iron that is sequestered, so I am trying to sort this out and determine whether I need to "unsequester" the iron before green sand filtering.

 

[basod]

You need to unsequester/oxidize the iron immediately before sending through the greensand and it has to be a controlled slower flow rate. It will also require that the sand be regenerated with potassium permanganate.

 

[deanchat]

Thanks! I have an idea about how to proceed. Will post it in the Deep End soon.
-Dean