UnknownStain - Fiberglass Pool

[mbar]

It may be a metal stain. If you have any ph down, or some vitamin C tablets, you can try it on the stain. Crush the vitamin C tablets up and rub it onto the stain. IF the stain goes away, it is a metal stain. You can also try some ph down in a sock and rub it on the stain. Your fiberglass pool will stain from metals very easily. Adding the soda ash could have reacted with the chlorine in the water and dropped some metals out of solution. If it is a metal stain, you will need to get some metal sequesterer, lower the ph down to 7.2 and add at least as much as it says on the bottle, more is better than not enough. IF the stain is not removed after a few days, then you can do a stain treatment. Let me know how you do, and feel free to ask any questions you may have.

[Skillset]

Hi Marie,

Thanks for your reply! Here's a dumb question, if the stain is at the bottom, how do you rub the crushed-up Vitamin C on it? Is there a technique to get the liquid onto the stain?

Same questions with the Ph-? Is there a technique for applying to the bottom of the pool?

The stain in the least shallow part of the water is at about 4' deep.

Is one test easier to perform under water than the other?

Thanks again!
Marc

[mbar]

You can tie the sock onto the skimmer pole and let it sit on the stain. You can put a couple of crushed vitamin C tablets in a thin sock or pantyhose, and tie it on the skimmer pole and let it sit on the stain. If you want to see if the stain is organic, then you can crush a trichlor puck up and do the same. If the stain is llifted by the chlorine tablet, then the stain is organic, and will lighten with high levels of chlorine. If the stain is from metals, then you will need the sequesterer or a stain treatment. Sometimes if the metal stain is new, you can lift it off with just the sequesterer. In my opinion it is a metal stain, because it fits with everything you have posted - and you have a fiberglass pool. You can read back through the metals forum and see that it is very common, and can be taken care of Let me know how the tests go, and I can help you further.

[Skillset]

A thousand thanks, Marie. I'll try to do the test today, but I need to do it when it's not sunny and, as you know, it's a beautiful day here in the tri-state area. So may have to wait a bit. Pool closes in 2 weeks, so I need to get it done! Hard to believe the the "gel" from a Vitamin C tab will remain in a sock, but I'll give it a try!

Do you have a San Juan pool ? I was wondering because the 16x33 is sort of uncommon (at least the 33 is) and we both have the same size. Mine's an Atlantic.

Anyone, I've been reading the manufacturer site and it says don't use a sequester (not even sure what that is). They recommend Jack's or Metal Magic. See: http://www.sanjuanpools.com/maintenance.html

Reading about Jack's, it says it's "heavier" than water, so I guess it floats down to the stain.

In any event, looks like it's treatable, which is great news.

Again, thanks!

[CallMeIshmael]

Hey Skill,
Just FYI, Marie (and WaterBear & ChemGeek & more- Thanks to you all!) have posted excellent details on those products, how they work, their compatibility with fiberglass, and the whole chelating/sequestering issue. You'll find tons of info by searching for Fiberglass Stains or those product names. I would post a link, but there are easily a dozen threads I've found invaluable. Best of luck tackling this before closing!

[mbar]

Sorry, but I never saw a vitamin c gel tablet. I have only had the solid form, so I don't know how you would get the gel on the stain without going in and rubbing it on by hand. Yes, it is a beautiful day, and I was just out getting the pool ready for closing I hate closing - it means it's the end of the summer. Anyway, I would just get the sequesterer for now, or not even do anything - I have closed with stains, and opened stain free. I think it may be that the the ph gets low over the winter, and as the chlorine gets low, the stains lift off. So in my experience, I wouldn't worry much about it, because you don't need to put any extra money in at the end of the season, and the stain treatments make it hard to rebalance the water - so if you want to close in the next two weeks, I wouldn't worry about the stain for now. If it is bothering you, you can do the sequesterer - I would recommend metal magic, because it is supposed to turn any metals in the water to salts, so they can be filtered out. Jack's magic is a very good product also, but it just sequesters the metals, unless you use the stain treatment which is ascorbic acid, and that will take a while to rebalance after the treatment. You also can't shock the pool for 2 weeks after the treatment, so you won't be able to close right away. Let me know if you have any other questions.

[Skillset]

I'm taking your advice - will probably treat next year. Again, thanks for your help.