Fiberglass pool badly stained

So glad you guys are back :)

Might as well be among the first of the needy !

Background, have a small fiberglass pool that uses a heat exchanger and a zone off our our boiler for heat. Works great. Last year I noticed that below the water line was becoming stained and couldn't figure out why. Tried metal out, jack's magic and a couple of other products with no results. Fast forward to now, pool is drained down about 1/3 and the staining is really bad, about the color of oak from the water line down. Figured I'd try some muriatic acid on a test area and it worked great for bringing it almost back to white. Gave the test area a good rinse when I was done.

I found the source of the metal and it was a couple of galvanized pipe elbows off the heat exhanger, they were very badly corroded inside. Replace them with pvc.

Well that a lot of baggage but there are a couple of questions coming:

I want to drain the pool, dry it, spray it with acid, rinse it and then refill it. Not much ground water underneath me, yard is quite sloped and the pool is at about mid yard. Anything to be aware of when draining it?

Next, muriatic acid and fiberglass, good idea or bad idea? Any precautions other than glasses, gloves and ventilation?

Last one, I'm sure there'll be some metal in the water still when I'm done, how can I get that out and prevent staining in the future?

Thanks for any help.

Mark

Hi, Mark,

Interesting problem. I will be using a heat exchanger this Spring, as well. I'll pay careful attention to the metal issue.

I'd get an opinion from a Fibreglas pool manufacturer about draining. Perhaps there's a way you can do a 90% drain and be a little safer. I wouldn't do it at all 'til I got a consensus from the fibreglas folks.:(

Ditto advice on muriatic to clean fibreglas. Good idea, just make sure it won't eat your pool:(

Not sure I understand your concern about future metal. If the galvanized was the source, and you eliminated it, why do you believe you'll still have metal content when you refill with new water?:confused:


Dave S.

Thanks Dave. I'm not getting too far with the manufacturer unfortunately so looking for the advice of the experienced folks here.

When you hook up your heat exchanger, make sure you use schedule 80 pvc, the regular stuff can't take the expansion of the heat exchanger and starts to leak, that's why galvie was put in mine and it was a bad move.

As far a metal content goes-- just don't want to have to go through this again so want to make certain that any old water or metal that's sitting in pipes, filter sand, etc will not cause staining again.

Thanks,

Mark

Hi, Mark,

There's not too many fibreglas owners on the forum here so you may have to be patient. (I'm not one)

Did you use PVC on both the boiler and pool side of your exchanger? If so, what temp is your boiler water coming into the exchanger? I'm thinking I'll probably use brass and PEX on the hot side and PVC on the pool side.

Since the metal precipitated out onto your fibreglas and you have eliminated the source, I don't think you'll have any further problems

Is your exchanger copper or stainless? If it's copper (on the inside), faulty pH can eat up the copper pipes pretty quickly. Stainless is pretty bullet proof but can still have some fittings that are just black iron that can lead to issues like you've experienced.

Dave S.

Hi Dave,

Boilder side is copper going in and out of the exchanger. Water temp I think is about 190. Pool water connections going through the heat exchanger have been my greatest source of difficulty and leaking. Sched 40, expands and contracts too much and eventually the teflon tape fails and it starts to drip. Galvanized pipe worked great for leaking but dismal for pool staining, a lesson learned. Shed 80 pvc loaded with teflon tape has worked out pretty well so far.

My exchanger is all stainless, works great but wish I went a little larger, too much hot water exiting the exchanger back to the boiler so I believe larger exchanger would have transferred more heat. Shouldn't complain though, I can raise the pool temp about 1.5 degrees per hour with the current exchanger.

Mark

hoogie,

I have a 16k gallon fiberglass pool. I have never drained it completely since the manufacturer told me not to as it will void the lifetime structural warranty. While building the pool, this concerned me so much I kept inquired about draining further. I found out fiberglass pools can in fact be drained if:
1. There isn’t any ground water under the pool. Mine has an access lid (identical to the skimmer) with a 12” plastic pipe that extends to the bottom of the deep end. Builder said this was for pumping out/inspecting ground water in case the pool needed to be drained.
2. The walls MUST be braced. One of the workers told me they use “spacer jacks” like the ones used in the back of a tractor trailer to brace loads. I’m not exactly sure how often/how many braces must be used. This is apparently to prevent stress on the walls from the settling ground around the pool.

As duraleigh suggested, I’d get a manufactures advice. Keep pressing them. If the original is no help, try C&W pools in Joelton, TN (615) 256-7329. They have been making fiberglass pools for 40+ years. I’m sure they'll tell you don’t do it but it may be worth a try.

Have you tried using ascorbic acid? It has worked wonders for me in the past. It is available several ways. I generally use a product called Stain Free however I have noticed several other products out there. Anything that says ascorbic acid (a.k.a. vitam C) should do the trick. It is around $40 for a dosage that treats my $16k gallons and I get it at the local pool store. I end up treating once a season to remove metal stains. Definitely try this before you drain your pool. I found out about it here on the forum after spending $100 on Jack’s Crap to no avail. It worked perfectly on the first treatment. Good luck.

Thanks David, I'll check into that. It would be mint if I didn't have to drain it.

Mark

http://www.chemistrystore.com/Ascorbic_Acid.htm

The difference between food grade and not is that when they get it in the box form from the manufacturer it is food grade. Once they re-package it in smaller quantities, it can't be sold as food grade. I found this out because last summer they ran out of the non-foodgrade containers, and he called me to ask if I would take the bigger box.

It is the exact same product as the pool store "Ascorbix" and the like and much cheaper. However, Acorbic acid does not fix your problem, it only helps you return the stain to "a solution". A sequestering agent, which you will have to buy at the Pool Store will "hold it there".

Read the Pool Docs Thread regarding Metals and Staining. All pools are different. And I have not found one pool store or pool maintenance company here in Southeastern Mass. that even remotely understands the concepts of this Forum.

I have a 35,000 gallon vinyl lined pool with a heater.My metal comes from my fill water, which is a well. The fill water has a very low PH {5.5}and High Mangenese. I have a very hard time maintaining the PH at 7.0 in my pool.
I chlorinate my pool with nothing but sodium hydro chloride, using a liquimate feeder in a 5 gallon gerry can, and 1/2 to 1 gallon of 12.5 per night.
I never allow my stabilizer level to go over 40.
Filter is 6 hours on, 6 hours off. The liquimate adds just enough SHC to keep me chlorinated . This formula keeps me stain free until the squestering agent wears off, or my ph rises to 7.4, at which point the metal falls of solution and stains my liner. Then I add the acorbic acid, it magically disappears, and the circle remains unbroken.

Good luck to pool owners with wells.

Hi Hoogie,
I think I can help you. First, the staining you see is a symptom of a much more expensive problem - corrosion of your copper heat exchanger. Metal corrosion is caused by acidic water, or water that has too low pH, therefore too much acid. Remember that in a fiberglass pool, the pool surface does not alter the water chemistry at all. If you are using tablet form chlorine (3" or 1" tablet) this is likely the cause. These little tablets are really convenient, but very, very acidic. Tablet chlorine has a pH of 2.9 - a lemon for comparative only has a pH of 2.0!! So, as they dissolve, they drop acid into the water. In a fiberglass pool, the surface isn't dissolving alkalinity into the water (as plaster does) so there is nothing to counterbalance this effect.

First to prevent the problem, watch your pH carefully and adjust weekly to 7.6. This will protect your very expensive heat exchanger also. Your test kit will tell you that 7.2 is "normal" however, we are "reading colors" which is a subjective matter. Keeping your pH a tish on the high side is less destructive than on the low side of normal, and you have a cushion, just in case you go away and forget to check it. Low pH is very destructive!

Now, how to fix this problem?? Easy. You can, of course use muriatic acid on a fiberglass pool, provided it is a quality shell. If it is an Aloha Fiberglass Pool, there is no problem whatsoever. I can't speak for other manufacturers. Be careful, though, Muriatic acid is nasty stuff. Wear your protective gear if you use it. But, there is another product that is nealy 100% effective at removing the stains, then keeping them away- Metal Magic by Haviland. 800-333-0400. Unlike Jack's Magic, which works some of the time, but not all of the time, because it is a sequestrant, not a remover. The first time you suprchlorinate, you destroy the protection. We've had amazing success with Metal Magic.

To keep the stains away, keep that pH at 7.6 check weekly and adjust as needed. Keep a metal removing agent in the water at all times. Metal Magic is a good product for that.

Quote:

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Originally Posted by alohafiberglasspools

Hi Hoogie,

But, there is another product that is nealy 100% effective at removing the stains, then keeping them away- Metal Magic by Haviland. 800-333-0400. Unlike Jack's Magic, which works some of the time, but not all of the time, because it is a sequestrant, not a remover. The first time you suprchlorinate, you destroy the protection. We've had amazing success with Metal Magic.

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My builder gave me two bottles of Metal Magic for my fiberglass pool after putting one in himself. It was no more effective than Jack's purple stuff that I also used. Looking up the MSDS for both products I found that they are both phosphonic acid derivatives as are the majority of stain and metal products on the market. My problem was a bit of rust staining and some concrete that hardened on the steps of the pool from the construction phase. The staining disappeard right away but the builder is still trying to get rid of the concrete! I think his theory was the low pH caused by these types of products would help dissolve the concrete.

Whoa, Guys, you've misread his posts (not that I've ever done that in my life:) :) )

The "pool" side of his exchanger is stainless steel...not copper. the "boiler" side is copper and it never touches pool water.

Secondly, I'm a little mixed up. Using muriatic to clean up an acid caused stain doesn't make sense to me. I'm missing something but I don't know what.:confused:

Off the subject, but muriatic is quite good at removing green masonry.....it's effectiveness diminishes as the masonry cures.:)

Dave S.

Quote:

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Originally Posted by duraleigh

Whoa, Guys, you've misread his posts (not that I've ever done that in my life:) :) )

The "pool" side of his exchanger is stainless steel...not copper. the "boiler" side is copper and it never touches pool water.
Yes but he stated that he found the source of the staining , corroded galvanized pipes which means the stains were iron--the brown stain commenly known as "rust" and he replaced them with pvc (the pipes, not the stains!)
Secondly, I'm a little mixed up. Using muriatic to clean up an acid caused stain doesn't make sense to me. I'm missing something but I don't know what.:confused:

The stain was caused by iron, not acid.
Chemistry 101 here(it won't be pretty!:D)....Ferric oxide (rust) is FE2O3 (sorry no subscripts) which means the iron is in it's trivalent form (+++ charge) which is not soluable. HCl will convert the iron to it's bivalent form (++ charge) which IS soluable and the iron goes back into solution in the water as an ion FE++. This is the way all those metal treatments and stain removers basically work on metal. They don't get rid of them they just put them into solution again ready to drop out when you least expect it. If you have ever needed to use one and the water in the pool has not been changed there is a very real possibility that you will continue to need to use them based on the chemistry of what they actually do.


Now to answer his questions. Since it has been determined that the HCL wont hurt the fiberglass pool and he intends to drain it that is probably the best way to get rid of the metals since he can rinse it afterward and drain to waste again. As far as treating the fill water, there are filters designed to remove iron specifically. If the levels are high that might be the best course.
Dave S.

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Hope that makes everything clear:rolleyes:

Mark,

This thread has become as convoluted as any post I've seen lately. I'm going to drop out with these thoughts.

I don't think it has been determined that acid will not harm your fibreglas. It probably won't, but nothing in this thread promises that.

Secondly, I would be very careful draining that pool. Fibreglas pools are designed to be kept full and draining one would, IMHO, jeopardize the structural integrity of your pool.

Dave S.

Quote:

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Originally Posted by alohafiberglasspools

First, the staining you see is a symptom of a much more expensive problem - corrosion of your copper heat exchanger.

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but . . .

Quote:

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Originally Posted by hoogie

Last year I noticed that below the water line was becoming stained and couldn't figure out why. Tried metal out, jack's magic and a couple of other products with no results. Fast forward to now, pool is drained down about 1/3 and the staining is really bad, about the color of oak from the water line down. Figured I'd try some muriatic acid on a test area and it worked great for bringing it almost back to white. Gave the test area a good rinse when I was done.

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Michelle, acid does not usually remove copper stains from surfaces. Copper stains are black or green-to-blue, not "oak" color.

Also, there are NO metal control products that are "removers". Proper use of some of them, IN CONJUNCTION with filtration, can sometimes 'stain' the filter, instead of the pool.

If you choose to address chemical issues, please be careful to post based on your own field experience, rather than what you've been taught in a sales meeting. Many of the things that everybody in the pool knows to be true . . . aren't actually true. So, if you don't know something to be a fact from your own experience, as a service tech or a chemist or a manufacturing engineer, please don't post it as if it's true. Instead, report it as "many in the pool industry think . . . " whatever it was you wanted to state.

We'd welcome any genuine expert knowledge you have . . . such as specific information about your company's products, or about FG pools generally, especially if you also know ways to solve those problems. "Poolsean" does this very well with salt products, including his own.

But, please avoid offering generic solutions that someone in your company believes in, unless you know for a fact that these solutions are valid ones. Using a liquid metal control product, like ProTeam's "Metal Magic" will not, all by itself, solve problems with metal staining. And the HEDP based "Metal Magic" will do virtually nothing to solve problems with the iron stains that are Hoogie's problem. Nor, as far as I know, will Haviland's product, which is called "Stain Elimitor" (their spelling, not mine!), not "Metal Magic".

Also, please note that I've added the required ID signature to your profile, so that any future posts will be properly identified, as required by the Forum TOS.

Thanks,

Ben

Metal Magic (MSDS showing HEDP content attached):
http://www.proteampoolcare.com/image...l_magic_07.jpg

Thanks all for the advice. Some good stuff in there.

I've been waiting until I had some info to pass on but unfortunately just looking for more advice.

I finally got in touch with someone at the pool manufacturer who had somewhat of a clue. Can't drain it or I void my warranty. They recommended proteam metal magic and said they would ship me some. Been waiting 3 weeks now, calling every couple of days and hearing excuse after excuse of why it didn't ship yet. I'm skeptical that it will work anyway. I've probably spent $300 bucks or so in the last year for metal something or others that did nothing but take the green color out of my wallet.

I read with interest about vitamin c. I took a tablet that I had, rubbed it on a spot for 30 seconds or so and the spot was nice and white after. Looks like it might work.

I also read about adding muriatic acid to the water to bring the ph real low to dissolve the stains then add a metal remover to capture and filter it out. Unfortunately no details other than read the bottle. The bottle of course doesn't say "If your a moron and have badly stained your pool add this amount" Anyone heard of using that?

I know I can get muriatic acid locally but not bulk vitamin c. I'd have to wipe out the vitamin section from every walmart for a 20 mile radius.

Anyone heard of the muriatic acid route before?

Thanks for all the thoughts and advice,

Mark

hoogie, There is a link to an online supplier of bulk ascorbic acid (vitamin C) on the first page of this thread.

Here is another link in case you want to get 5 lb.:
http://www.msm-msm.com/store/agora.c...scorbic%20Acid
You bring your ph down, and lower your chlorine (the ascorbic acid will be used up by the chlorine) Just pour the ascorbic acid down the walls of the pool as you walk around. Put the filter on circulate, dump in enough metal sequesterant for the size of your pool and let it circulate till you see all the stains magically disappear! It doesn't take long. Then put your filter back to filter and keep it on 24/7. After 24 - 48 hours you can start to SLOWLY bring up your chlorine level. If you have a sand or DE filter you can put a chlorine puck in the skimmer, which will help to let the metal stain the filter instead of the pool. Youwill also have to bring up your ph level. After a stain treatment it is hard to keep the ph and chlorine up. Don't let the ph go higher than 7.2 for a while, and do not get your chlorine up to shock levels for at least 2 weeks. High ph and high chlorine will make any metals in your water percipitate back out to land on the pool. If you have any questions feel free to ask.

Okay, here's an update. Happened to stop at a pool place today and they happened to have absorbic acid. Bought 10 lbs. I explained my dilemna to the pool guy there and he said to take 5 lbs, mix it in 5 gallons of water and use a mop and swab in onto the sides, bottom, steps, etc.. -- even though they are underwater. I did that, pain in the butt.

I also took an extra step and sprinkled the last 5 lbs down the walls and onto the stairs and benches. Threw in a half a bottle of stain-x for metal, put the filter on recirculate, closed the cover and let it run for about 7 hours. Chlorine was nil and ph was about 6.0 when I started.

Well, just opened the cover and it did NOTHING. Still brown as ever... I'm bummed. I'm seriously considering just draining it and spraying it with muriatic acid which I know takes the brown right off. Nasty stuff but it's turning into a money pit otherwise. Besides having brown walls, the water is cloudy and looks like crap and will probably take a bit of work and $$ to get it right after this. I'd seriously like to just start off fresh.

So who can offer advice about draining my 11x24 fiberglass pool safely? Manufacturer told me not to as it voids the warranty.

My yard is sloped so I know there's no standing water underneath it. Concrete deck all around so chance of cave in is minimal.

I may rent some trucks jacks for support, gas mask of some type and then just spray away, wipe clean and refill it. Shouldn't be empty for more than 24 hours. BTW, the pool is enclosed so no elements to worry about either.

Anyone have any other advice I should consider?

And again, thanks everyone for the well thought out responses. I knew this was going to be tough one.

Hoog

I really don't understand - if a vitamin C tablet worked, then the ascorbic acid should have worked. The low ph and no chlorine should have made this a snap. Are you sure it was ascorbic acid or oxcylic acid? I am really stumped. You can contact the pool company and ask them the best way to drain - they have to drain them when they have to fix cracks on the bottom. I have a friend who had to have this done, I will call her tomorrow and ask her how it was done. You must really be frustrated! I feel your pain. Keep the faith!!

I'm finally stain free !!

What I tried with the pool filled with water:
Jack's magic
Abscorbic acid
Oxalic Acid
Proteam Metal Magic
Various metal stain removing agents
Scrubbing
Vitamin c in a sock

Abscorbic acid was the most promising but it only lightened the stains a bit even after 20 lbs in a 7000 gallon pool.

What finally worked for me:

Drained pool
Sprayed sides and bottom with a 1 to 1 mix of muriatic acid/water.
Tougher areas got straight muriatic acid.
Rinse pool, drained whatever water was left.
Refilled pool and used a metal remover, sorry can't remember the brand but was used as a precaution.

Muriatic acid is nasty stuff and even with protective clothing on I got a few burns on my skin. 1 to 1 mix didn't smell that bad but the straight stuff had a gagging smell once applied and if it weren't for it being a good windy day when I did it, I'd probably be dead.

Not suggesting that anyone else drain their pool but for me after probably $600 in metal removers, scrubbing, mopping stuff on under water, etc. draining and spraying was a last resort and it worked beautifully. My pool and water look cleaner and brighter than ever. If I ever run into this problem again I'll be draining and spraying in an instant. It took one day from start to being full of clean water again.

Thanks everyone for all the suggestions and support.

Hoog

Congratulations!! Now, enjoy your pool.