Drained pool, help ID these stains on surface

tangouniform

Well-known member
Apr 11, 2014
62
Central Tx
#1
I've been dealing with a staining issue the past couple years that I haven't been able to remedy so I decided to drain this year to see if I can get a better look at the stains and to see if I can tackle the issue. I'm dealing with two separate stains here. The entire gunite surface is covered in what looks like a green stain which is shown in the pics. I also have a lot of brown staining at various parts of the surface which is shown as well. Last year I tried a no-drain acid wash which did pretty much nothing. I also tried the vitamin C and chlorine tablets on the stains last year to no avail. Any help?

BTW, all these pics are taken after I pressure washed the entire surface.




 

JamesW

TFP Expert
Mar 2, 2011
12,819
#2
Looks like multiple issues including copper, iron, scale, etching and it even looks like the pool was painted at one point.

I would suspect that the chemistry has been all over the place.
 

tangouniform

Well-known member
Apr 11, 2014
62
Central Tx
#3
Looks like multiple issues including copper, iron, scale, etching and it even looks like the pool was painted at one point.

I would suspect that the chemistry has been all over the place.
Anything I can do right now while the pool is empty to make the surface look better?

Would an acid wash help or possibly hurt considering the condition of the surface?
 

JamesW

TFP Expert
Mar 2, 2011
12,819
#4
The surface is in rough shape. An acid wash might clean it up some but will make it very rough.

Not a lot of good options.
 

DeanP66

Well-known member
Mar 26, 2014
702
San Jose, CA
#5
My pool had similar stains to those(probaby worse) about 2 months ago and I decided to drain and do an acid wash. It was pretty easy once I got the water drained and although my plaster has seen better days, it cleaned up nicely after the acid wash. I just used a watering can with about 8 gallons of Muriatic acid (full strengh) and diluted it in the watering can with water to about 2 to 1 acid to water ratio. I poured about a 7 to 10 foot section at a time and scrubbed it with a brush as well and hosed it off toward the deep end where my utility pump would pump it out of the pool. When I finished the entire pool I did a little touch up in spots that I wasn't quite pleased with and when finished, I refilled the pool. Came out really nice.