Metal staining/FG pool-updated and more questions

[moppymo]

Hello,

We had some staining on our approx. 11, 300 gallon fiberglass pool. I used the vit C to check and sure enough it cleared up the areas I dropped the tablets very well. So, some sort of metal staining was taking place. This is our second year with the pool. We didn't have staining last year but this year it seems to have progressed over the course of the summer. Fall, winter and spring it was fine.

So, try as I might, I do not understand pool chemistry very well but we test with a TF100 test kit and try to keep things balanced. I'll include last nights numbers.
FC-1.5
CC- .5
CL- 1
PH-7.8
TA-100
Didn't test for CYA or CH.

Our pool has a SWG- however, we have no idea how to tell what salt rate we have so we guess. I know... Trust me, we have tried to figure this out, it came with very little instruction(from the PB) and it seems even less is available online. We bump it up or down depending on if it seems too salty. I think it is currently set to 20% because the water seemed too salty recently and we dropped it down a bit.

Anyway, at about midnight, I added a bottle of Pool Time, Metal, Stain and Scale Out from Home Depot. I don't have time to wait to order online and need this pool straightened out fast!! I didn't brush the walls or anything. The additive is some sort of PHOSPHONIC ACID, I believe. While it appears that the staining is lighter, it is still there- albeit very faintly. I'm considering adding a second bottle today while my chlorine is still on the lowish side to see if I can kick it completely. Advice? It says not to add more than 3 bottles and after seeing what one can do, I think a second may complete the stain removal, however is there something else I need to add after it appears clear? Do I hose out my filter? It seems to be running high, there is more pressure showing on the gauge. My ph was not low enough but I added the metal remover stuff because I'm short on time and trying to do this alone. I need to get this pool "healthy" again as quickly as possible. I'll have to leave it unattended while traveling and don't want to come home to an out of control science project. I also have four anxious kids who want to swim. At what point do I dare allow them back into the pool?

Thank you so much!!

 

[moppymo]

Re: Metal staining on FG pool

Upon further evaluation, (the sun isn't shining on the pool like it was earlier)- the staining is NOT diminished after all. Perhaps I used the wrong chemical or not enough? However, there are now small rusty spots-(like cupcake sprinkles) sprinkled about on the fiberglass that are evident and I don't recall seeing them previously.

Should I call a pool store and ask them for another chemical additive- the ascorbic acid? If so, can I still add it despite using the Pool Time Stain, Scale stuff?

My numbers from 11;00 am today are:
FC- 5
CC-0
CL-1
PH-7.8
TA- 100
CH-110
CYA-out of chemicals and can't run.

 

[moppymo]

Did I post this in the wrong section? Does anyone have any advice?

 

[Bama Rambler]

Let me try some of it. Since you don't have results for the CYA I'll be stabbing in the dark a bit.
Your FC is really low.

Adjusting the percentage on the swg doesn't have anything ot do with the salt level. It adjust the chlorine output of the swg. You need to raise it until you get the proper FC in the pool.

Since th vitamin C tablet test worked you probably need to do an AA (ascorbic acid) treatment on the pool to get it cleaned off. Adding sequestrant won't cause a lot of the staining to lift. It will keep it from redepositing once you get it off but it won't remove it.

 

[toofast]

Not sure this is the right section...but your rate adjustment on your SWG has nothing to do with your SALT LEVEL - it is how much chlorine to generate.

I think the other issue is you are just pouring stuff I the pool without waiting for a bit of help...finally, in cases like this, a picture is worth a thousand words...post if you got em.

(EDIT - looks like we posted at same time and you are getting some help)

 

[moppymo]

Hi and thank you both so much for your responses!

Dave J.- Thank you for your thoughts. Was what I added a sequestrant? If so, I didn't realize it was. I found another local store that sells, Stain Free, Stain Out and they also have Metal Out. Perhaps I should use one of those? I'm calling around trying to find the AA locally, however not having good luck. I don't have time to wait to have it shipped here since I'm scheduled to be away and my pool will be tending itself on a timer.

Toofast, Thank you for your feedback. Unfortunately, I am/was in a huge bind for time and needed to get started. Doing something seemed better than doing nothing, particularly with my chlorine levels being so low. I really don't want to create a further mess. I will attempt to get some photos, however, the staining is quite light and hard to see in photos. I'm temped to bring my chlorine back up and leave the pool alone until after my trip. It may reduce my concerns and time constraints. I just don't want the staining to get worse.

Where would you suggest I post this if not in the Chem. 201 heading?

 

[Bama Rambler]

Yes, what you added was a sequestrant. The type with phosphonic acid is the type we recommend here.

 

[moppymo]

Hi Dave J.
Thank you for your response. So, would you think I should wait until after I travel to mess around with removing the staining? It is very faint when I compare it to others I see posted online. It is noticeable to us because the pool was brand new last year. I'm just concerned that if I leave it unattended with the pump running, after treating it, we could end up with other problems.

Or maybe I just hire a pool sitter while I'm away....

 

[Bama Rambler]

Since you have the sequestrant in there, I'd wait till after the trip to work on the staining. You may find that they've lightened a bit with just the sequestrant in there.