High iron content in my city water

[road_warrior]

Pool and forum newbie. Thanks for the great forum.

I've done a lot of reading here so far after turning my new pool water brown. So now I know my city water has high iron content. I've read a ton about getting rid of the brown water and am doing that now.

So now I'm focused on how to avoid brown water next year. I don't think I fully understand the concept of keeping the iron in suspension. Do you have to keep sequestration agents in your pool all year? Or do you just need to do it long enough to filter out the (invisible) iron somehow?

[aylad]

Hi, and welcome to the forum!!

You can handle it two ways: you can 1)just keep adding sequestrant agents in the pool all year, or you can 2)try to actually get the metals out of the pool. If you just want to go the sequestrant route, just keep in mind that it will take regular doses, since the sequestrants are eventually broken down by chlorine. If you want to remove the metals, there are currently 2 methods being used around the forum--the first is the use of a Culator, a small bag that lives in your skimmer and slowly collects the metals from water that has the metals sequestered in it by use of HEDP sequestrants, and the second is an intentional staining of the filter media by running the water over a high chlorine source (like a trichlor puck in the skimmer) right before it hits the filter, so that the metal falls out and is trapped in the filter so it can be backwashed out.

BTW, welcome to the forum!

[PoolDoc]

So now I'm focused on how to avoid brown water next year. I don't think I fully understand the concept of keeping the iron in suspension. Do you have to keep sequestration agents in your pool all year? Or do you just need to do it long enough to filter out the (invisible) iron somehow?

You only want to keep it in suspension, till you can remove it. And you usually can't remove "invisible" -- dissolved -- iron. What does seem to happen is that if you:
1. use an effective sequestrant (ie, HEDP!), and
2. filter continuously
THEN, as the iron comes out of solution it more often gets caught in the filter than by the pool.

But, this is somewhat hit or miss.

What you might want to go ahead an try this summer is a trial run of HEDP + CuLator. We've seen a fair amount of evidence that the CuLator does work, and IF it works, it DOES remove dissolved iron. (In fact, it's useless against visible or precipitated iron.) You are going to have to add iron, every time you add water, and that's going to give you an opportunity to practice.

If you want to do so, do these things:

1. Get a K2006 test kit -- get an HTH 6-way at Walmart as a daily kit, if available.
2. Get some HEDP
3. Get a CuLator unit AND a set of skimmer socks
4. Put the CuLator in the skimmer, under a skimmer sock (to protect the CuLator from being ruined by goo)
5. Add a 1/8 dose of HEDP EVERY time you add water to the pool.
6. Keep your pH at the low end of what's acceptable for your pool, probably 7.0 - 7.4 (Helps keep iron dissolved).
7. Let us know how it goes -- we'd LOVE to have photo of the Culator, cut open at the end of your pool season.



Products for metal control and clean-up:

HEDP is a liquid phosphonate that is pretty chlorine stable, and very good at keeping dissolved metals IN the water, instead of ON your pool surfaces. It can lift recent stains, OR it can be used along side of ascorbic acid, to keep the metals in the water, after the ascorbic acid is consumed by chlorine.

Jacks Magic The Pink Stuff 1qt (60% HEDP) @ Amazon
20% KemTek HEDP @ Amazon

Using polyquat during metal clean up accomplishes two things: it helps kill or prevent algae, letting you run lower chlorine levels, and it is a very good clarifier, that helps you filter out any small metal particles that may form.(Probably available from pool stores, and possibly some big box stores -- but you MUST learn to ID it correctly. See the polyquat page for more info.)

Kem-Tek 60% polyquat @ Amazon
Nava 60% polyquat @ Amazon

Ascorbic acid (Vitamin C) can be used to remove copper and iron stains from pool surfaces, and put the metal BACK into your pool water. (Not likely to be available locally, except as Vitamin pills.)

Ascorbic Acid Powder @ Amazon
Ascorbic Acid Vitamin C Powder USP Pharma Grade 11 Lbs @ Amazon

=> Do NOT use the Vitamin C, without understanding the whole step-by-step process. It only works if you do everything in the right order. (Sort of like breaking eggs, before you scramble them, instead of after )

The CuLator product is a special patented plastic material, contained in a bag that goes into the skimmer, that can slowly take metals OUT of your pool water. We think it works, and have some evidence that it does, but not proof yet. (Not likely to be available locally.)

1 ppm Culator @ Amazon
1.5 ppm Culator sold by Amazon, shipped from Periodic
4 ppm Culator sold by Amazon, shipped from Periodic
Poolmaster 16242 Poolmaster Skimmer Basket Liner @ Amazon (to protect CuLator from being damaged by scum)

[road_warrior]

Thanks for the great info. It makes sense the dissolved iron can't be filtered.

I have an Intex 14' x 48" pool, Intex SWGC, and an Intex Sand filter if that makes any difference for my choices.

I did get the 6-way test kit from Walmart and I'm still trying to lower my alkalinity. Took the plunge today after my pH minus ran out and picked up the muriatic acid from Home Depot and looked like Breaking Bad in the back yard today.

I'll update my results when I have to fill again. I might have to try that CuLator.

On a related note, has anyone tried or had any luck with garden hose filters, specifically the ones designed for RVs?

[Watermom]

Don't know about the garden hose filters, but here is the link to the CuLator.

CuLator - 1.5 ppm unit @ Amazon
CuLator - 4 ppm unit @ Amazon

[PoolDoc]

I'll update my results when I have to fill again. I might have to try that CuLator.

You have to use HEDP + the CuLator -- HEDP, to keep it dissolved, and CuLator to remove it.

On a related note, has anyone tried or had any luck with garden hose filters, specifically the ones designed for RVs?

What's worked have been home-grown arrangements that filtered AND simultaneously exposed the water to air. Most likely, until your water is exposed to air, the iron is dissolved, and won't be filtered by a closed RV unit. Now, if you aerate or chlorinate BEFORE it goes through the filter, that's a different story.