Stains in Fiberglass pool

[Arizonaoldman]

I tried the Vitamin C Tablet today. Got it wet then used it directly on the stain.
No luck whatsoever. Tried Mr. Clean Magic Eraser yesterday, still no luck. I refuse to give up.

Ralph

[mbar]

I read somewhere that you can put a little ph reducer in a sock, wet it, and rub it on the stain - if it is mineral it should take the stain off. You probably would want to wear gloves when doing this. Let me know if this helps. I wouldn't give up either!

[DavidD]

You are in good hands Ralph. Marie (mbar) helped me allot a couple of years ago and turned me on to the Vitamin C. I owe her much gratitude. I too have a Fiberglass pool and seam to have to treat my pool a couple of times each season. On another thread, waterbear has brought to light a yet unsubstantiated claim by a company (Water Tech I believe?) that a lack of calcium could cause problems in vinyl/fiberglass pools. No one is sure if this is true yet and I personally have my doubts but just for the sake of "research", would you post your numbers? Mine are as follows:

FC 3
CC 0
TC 0
PH 7.5
ALK 80
CH 60
CYA <30
Temp 84
16,000 gallon I/G Fiberglass

I currently have stains. My stains generally appear as grey lines running from one side of the pool to the other. They even appear as orange/yellow sometimes in certain light. The pool has been open for a couple of weeks now and the stains have progressively gotten worse. The last treatment was in August '05 and I'll be giving it the ascorbic treatment after the weekend. I'm trying to keep a log to try to figure out what is causing these stains and would like to compare others numbers when staining has occurred. I use a water filter (cheap RV type) when filling and have had my water tested for metals and there are no traces of Iron or Copper. Notice My Alk and CH are low? I'll be working on those after the treatment next week. I usually keep ALK between 90 & 100 and have never worried about CH but it has never been this low. I did do a partial drain when opening to get the CYA down and I guess the filter is working since no calcium seems to be added. Thanks in advance for your help.

Dave

[mbar]

Hi Dave, I am still trying to figure out what causes the stains. Your numbers seem perfect to me. Have you added any sequestering agent since opening? I also read somewhere that "Fiberglass has a negative electrical charge and can attract positively charged metallic ions, causing the development of a stain. The periodic addition of a metal treatment should help negate this effect and help keep pool stain free. " I don't know if any of this is true - but it would seem to be a reason that the fiberglass stains so easily. I haven't opened my pool yet this year, probably in about 3 weeks. I plan to add sequasol first before anything, then test all the chems and bring up the chlorine slowly. I think the most important is to have the sequestering agent in the water in a large quantity before doing anything at all, including a stain treatment. Maybe between all of us we can figure out why we get the stains - we know how to get rid of them, but it would be nice to not ever get them!

[waterbear]

I also read somewhere that "Fiberglass has a negative electrical charge and can attract positively charged metallic ions, causing the development of a stain. The periodic addition of a metal treatment should help negate this effect and help keep pool stain free. " I don't know if any of this is true - but it would seem to be a reason that the fiberglass stains so easily.

Can you substantiate this in any way? I would be interested in knowing where this statement came from.

[mbar]

I was googleing stains on pools, and I came accross this website:

http://www.askalanaquestion.com/pool...ems-page_2.htm

There is a whole archive from "Ask Alan" on pool stains. I am going to search some more and see what I can find out about it. If anyone else has any information it would be greatly appreciated!!

[DavidD]

Marie,
I have not added a sequestering agent yet but had planned to after I did the ascorbic acid treatment. I would usually then backwash/replace DE and add more sequestering agent after all is said and done. Maybe I'll try just the sequestering agent first and see what happens. I'll let you know.
Now let me clarify, these stains are not that noticeable in full sun but usually in low light, such as evening, and I notice them more than others (maybe OCD?).
One observation I have made so far is that the stains appear to be occurring where the gel coat was sprayed in intervals. This is the only explanation for the almost perfectly straight lines that divide my pool in to 3 equal parts. I know that when gel coat is sprayed, you can usually only spray up to about a gallon or so at a time due to "kick off " times (the time in which the gel coat will start to cure). So it appears that where one part overlapped the other, staining is more prone. Makes we wonder if maybe there are slight indentions or something in these areas that collect the stains. After all, fiberglass/gel coat/resin is not absorbent so the stains occur at these locations for some reason.
Either way, It really isn't that big of a deal and if I had to do it all over, I'd still choose the same pool, stains and all!

[mbar]

Me too Dave! I love the fiberglass, stains and all. I noticed the same thing - my stains always seem to appear in the same places. My opinion is to put the sequestering agent in first, so whatever metals are still in solution will be filtered out. Then again when you do a stain treatment, so that the metals will bind to the sequestering agent as soon as they go into solution. My plan this year when I open is to put in the sequestering agent, slowly raise my chlorine, and balance the pool. I plan to run low cya (about40) so that I don't have to keep my chlorine very high. I also plan to keep my ph around no higher than 7.4. What I think, and it is only what I think so far, is that when the ph is low, the chlorine is more potent, which can let any metal in the water fall out onto the surface of the pool when the filter is off and the water isn't moving. But on the other hand low ph keeps the pool on the acidic side, which keeps the stains in solution, making the sequestering agent able to get rid of the stains before they fall onto the surface of the pool. This is why it is so confusing. So in my opinion lower ph with lower chlorine levels should keep the pool less suseptable to stains. I really don't know yet!! I am still in experimental stage - every time I think I know how and why the stain comes, something happens to destroy my theory. Anyway this is my plan for this year, I will let you know how it goes. I think keeping the filter running for 24/7 for the first couple of weeks after adding the sequestering agent is the most impotant thing when I first open the pool. I have never had stains when the pool is first opened, it seems it happens when I shock the pool on opening. That's why this year I plan to put in the sequestering agent first before taking the water up to shock levels. Keep me informed on what you learn too, maybe we can figure this out!

[wsmith002]

Every year it is the same thing for us. Once the chlorine level goes up, light brown stains on the floor, steps and sides begin to appear. StainFree (Vitamin C) will take then up for a couple of days then back them come. Pool builder just says it's something I'm doing. The only place not stained is the seems on the bottom.

[cajunfla]

OK, I guess I will be joining this thread. I have the dreaded brownish stain all over the fiberglass below the waterline. Did a partial drain today, mostly to get rid of HIGH CYA. Tried scotchbrite pads, even pressure washer. NO JOY !

Going to try the Stain Remover (ascorbic acid) from Leslie's. The lable says I must use with Metal Free to pevent re-occurance. Buying that brand because I don't want to wait for a shipment. I will add to pool after re-fill is complete, and post results of stain removal tomorrow.

Jeff