Ascorbic acid treatment for stains, which sequestering agent to use?

[PoolDoc]

I'm working on a chemical sources page, like the new test kit page (), but haven't finished it.

The sequestrant is HEDP. It's widely available BUT in mystery blends. So get this one -- EXACTLY this one, from Amazon:

KemTek 20% HEDP @ Amazon

Usually, I say "or one like it" -- but in this case, get this one EXACTLY. It's the only HEDP product where I know the exact ingredients. I'll edit the Vitamin C sticky to include this.

You may get ascorbic acid (Vitamin C) at Amazon as well.

Also, there's a problem with the Vitamin C treatment: it lifts the stains OFF the surface, and put's them BACK into the pool water. But, the metals can RESTAIN your pool. We're seeing some indication that this product works as advertised. If it does, it will remove the metals from your pool water

CuLator - 1.5 ppm unit
CuLator - 4 ppm unit

If you get one of these, do NOT start using them till AFTER you've 'lifted' the stains.

Also, the CuLater package will probably NOT be used up when you're done, especially if you get the higher capacity one. You can probably remove it, and store it in your fridge in DISTILLED water, and then reuse later in the season. (I'm gonna check and see, but Periodic Products won't like that approach, so I'll have to be careful how I ask.)

--- I'm gonna update the Vitamin C sticky and the add some more comments to this thread --