Help! Plaster stains (pixs included)

[cflannagan]

Plaster is real old (probably 15+ years). Is there anything I can do about removing those tiny stains found generally throughout the pool, plus some big blotches and some staining on stair edges?

Or is it hopeless cause (I should consider resurfacing)?

Test results (first-tft-100-test-results-t29769.html):
Date: 4/8
Temperature during day: ~75 F
FC: 17
CC: 0
TC: 17
pH: 7.6
T/A: 130
CH: 360
CYA: 40?

 

[JasonLion]

Try holding a vitamin C tablet against a stained area for about 30 seconds and see if the stain lightens or goes away. If so, you can clean up the entire pool using ascorbic acid or citric acid. If that doesn't work, there are a couple of other things you can try.

 

[cflannagan]

Try holding a vitamin C tablet against a stained area for about 30 seconds and see if the stain lightens or goes away. If so, you can clean up the entire pool using ascorbic acid or citric acid. If that doesn't work, there are a couple of other things you can try.

Yep, big difference when I held an Airborne (pink grapefruit) against the stained area for 30 seconds, leaving behind a nice white/light blue (whatever color the plaster is) circle in middle of the stained area.

What's next? :-D

 

[JasonLion]

You should do an ascorbic acid treatment. There are detailed directions in this topic.

 

[cflannagan]

You should do an ascorbic acid treatment. There are detailed directions in this topic.

Just read the thread in your link; the first post advised bringing my chlorine level all the way down to 0; should I really bring chlorine down to 0 with my CYA level being where it is (risking algae issues)?

I was wondering.. (which of course could be wrong, please let me know): let my FC fall on its own (it's at 17 now), until it is down to the ideal FC level for my CYA level, and then doing the acidic treatment? I understand that I might need to add more acid than I would if I was at 0 chlorine level. I am just worried about potential algae outbreaks with my CYA level while we are well into the swimming season here.

 

[JasonLion]

Ascorbic acid and chlorine destroy each other quickly before the ascorbic acid can act on the stains. You can't do an effective treatment unless chlorine is zero. Ascorbic acid is fairly expensive, not a cost effective way to bring your FC level down. You could bring FC down with a chlorine neutralizer, like thiosulfate, if you want to.

Most people get algae during an ascorbic acid treatment, but if you are careful and use polyquat algaecide you don't have to get algae.

 

[cflannagan]

Hello everyone!

Now I'm revisiting this topic (I was going to wait until a few months before swimming season begins).

Basically, my plan looks like this:
[*] Order 2 pounds of Ascorbic Acid: http://www.chemistrystore.com/Chemicals ... _Acid.html
[*] Buy sequestering agents
[*] Let Chlorine level go to 0
[*] Going to follow steps outlined here: ascorbic-treatment-to-rid-pool-of-metal-stains-t2298.html

I have questions:
[*]Other than letting chlorine level go to zero, is there any other chemical balancing I should do before treating pool with ascorbic acid?
[*]If possible, I'd like to eliminate any source of staining. I've included a picture of pool piping going into our heater. We have not used this heater (it's quite old and in bad condition) and will replace it eventually when we are ready, but is it possible that those metallic pipes might be big contributors to the pool staining? If so, I'd like to see if I can hire pool handyman to disconnect pool piping from the heater so the staining problem does not return eventually.

Thanks in advance!

 

[susa]

>> I should consider resurfacing?

Yes

 

[duraleigh]

but is it possible that those metallic pipes might be big contributors to the pool staining?

Probably not the stainless steel pipes but your heater core could be contributing. If the water is circulating through the heater and you aren't using it to heat the pool, it is a VERY simple process to disconnect the two pipes at the bottom with those unions and simply put a "jumper" made out of PVC.

It sounds like you are not too familiar with the heater so I think that would be a good plan to have a pool guy "eliminate" it from the system

 

[cflannagan]

>> I should consider resurfacing?

Yes

Erm, I think I'll take advice from the real experts, especially since we all have established that those staining are actually treatable.

but is it possible that those metallic pipes might be big contributors to the pool staining?

Probably not the stainless steel pipes but your heater core could be contributing. If the water is circulating through the heater and you aren't using it to heat the pool, it is a VERY simple process to disconnect the two pipes at the bottom with those unions and simply put a "jumper" made out of PVC.

It sounds like you are not too familiar with the heater so I think that would be a good plan to have a pool guy "eliminate" it from the system

Sounds good. You're correct that I'm not really familiar with the heater and we'd rather have something newer in its place (we got this house 2 years ago).