Salt Water Stain Removal

[JimK]

I have the same understanding as you. Having been through the AA stain removal treatment before, I don't want to do it again.

If it's not the salt that's adding metals to my pool, then it has to be our city water (despite the post from Sean {no offense Sean })I still suspect the salt/SWCG system since it's only an issue when running the SWCG). There's no equipment or anything else that I put in the pool that would be adding metals (thanks to the methods taught here, there's not much I have to add to the pool ). And since city water is the only source of water I have to top off the pool when we don't get enough rain for awhile (not often), I'm stuck dealing with it.

It's been reported here that Jack's Magic Pink Stuff is more concentrated than the Purple Stuff I've been using, so I may give that a try so I can use smaller doses/use less. However, I'd still like to know what is it about the Purple Stuff that makes it more suitable for salt pools, or is it just marketing BS?

PS - I find it interesting that a couple of coworkers of mine who use the same SWCG system (one has a vinyl liner IG pool, the other a fiberglass IG pool; we are all on the same city water system) have the same issue I have.

[SunnyOptimism]

I have the same understanding as you. Having been through the AA stain removal treatment before, I don't want to do it again.

If it's not the salt that's adding metals to my pool, then it has to be our city water (despite the post from Sean {no offense Sean })I still suspect the salt/SWCG system since it's only an issue when running the SWCG). There's no equipment or anything else that I put in the pool that would be adding metals (thanks to the methods taught here, there's not much I have to add to the pool ). And since city water is the only source of water I have to top off the pool when we don't get enough rain for awhile (not often), I'm stuck dealing with it.

It's been reported here that Jack's Magic Pink Stuff is more concentrated than the Purple Stuff I've been using, so I may give that a try so I can use smaller doses/use less. However, I'd still like to know what is it about the Purple Stuff that makes it more suitable for salt pools, or is it just marketing BS?

Yeah, I doubt it's from the salt. As long as you're buying salt meant for pool use and not some random water softener grade salt, it should be fine.

Two thoughts -

#1 - It is not at all implausible that your SWCG could be a culprit. The water chemistry environment INSIDE the cell when it is generating is very, very fdifferent than the bluk pool water. The pH is generally higher because of the chlorine production (rising pH) and the alkalinity is very low due to CO2 outgassing. So, if the water has metals in it, it is possible that your cell's chemical environment is causing the metal to scale out of solution and then it is being deposited wherever the returns are.

#2 - Have you checked your cell recently? It is always a good idea to check your cell's anode & cathode plates (as best as possible) to ensure that the precious metal coating (some mixture of titanium, platinum and rhodium) is not chipped, scratched or damaged. The underlying plate surface is likely either copper or stainless steel (copper be more likely) and you would definitely NOT want that exposed during cell operation.

#3 - Can you get water quality reports from your municipal water supplier? Typically the EPA requires that all municipalities test their water supplies and provide report data for all metals. Alternatively, you could try to bucket test your supply water to see if it scales out metals.

Just some thoughts...

[JimK]

Thanks for your feedback.

Yes, I do inspect the cell periodically. No problems there.

As I mentioned, the stains first appear on the steps. There is a return in the steps and the steps are white, which is probably why I notice it there first.

I'll see if I can find water quality info on our city water.

I take it a passing bucket test for metals doesn't necessarily mean the water has no metals, perhaps just a low level of metals? When I did the bucket test there was absolutely no staining/discoloration in the bucket.

I do stick with "pool salt" that says "no additives". I do not use water softener salt.

[SunnyOptimism]

SWCG Cell OK? CHECK!

Salt is pool-grade (no additives)? CHECK!

Fill water? Jury still out....

As for bucket tests, those really won't work so well in my case. I have high CH from being in the Southwest (CH ~ 500ppm), so the only thing that would scale out in a bucket for me is huge amounts of calcium. But that does bring to mind another problem which may not be a big deal for your vinyl pool - sequestrant interference. It is well published on the Taylor website and in other forums that the calcium hardness test, which uses EDTA drop-wise to chelate the calcium ions and cause the indicator dye to change colors can be interfered with by the presence of a sequestrant in the water. Now this all depends highly on the chemical affinity of the sequestrant you use versus EDTA for the Ca ions but it is possible to slow down or arrest the color change of the CH indicator dye. SO it makes me wonder in high CH pools if Jack's Magic goop (HEDP mostly) would even work all that well considering the sequestrant will go after the Ca ions just as easily as any metal ions.

What's your calcium hardness? I know you operate a vinyl pool and probably don't test for it very often, so an old number is OK.

As for Jack's Pink versus Purple, etc...if it's all HEDP and just different concentrations in the bottle, then I don't see why it would matter at all if you have a salt water pool or not. I think I read somewhere on here once that it is indeed just marketing, so you can probably ignore it and just buy the color of Jack's Magic potion that works best for your water.

I think someday I'd like to modify an exercise bike to run a small water pump and then hook an inline filter up with those Culator bags and use the energy produced by my much needed workout sessions to help filter my pool water....beats paying the electric company I suppose

[JimK]

Before discovering this site, I use to maintain CH at about 250-300 by adding calcium flakes and/or cal-hypo if I was shocking the pool. Since I always had to add calcium to keep it at the desired levels, I assume that my fill water isn't adding a significant amount. It's been about 3 years since I've added any calcium. Last season I checked the CH level and it was about 200.

The Purple Stuff works very well preventing stains in my pool . I usually only have to add half the recommended weekly maintenance dose to remain stain free. I'm thinking with the higher concentration Pink Stuff I could probably use even less.

I will be closing the pool pretty soon, so trying the Pink Stuff will have to wait until next season (I can't believe the season is ending already! ).

Hmmm...maybe I can attach CuLator bags to my swimsuit and remove metals while swimming.

[SunnyOptimism]

I will be closing the pool pretty soon, so trying the Pink Stuff will have to wait until next season (I can't believe the season is ending already! ).

Closing.....what does the mean.....

[JimK]

Sure, rub it in.....