I dropped a Vitamin C tablet in the pool on top of a small green stain. It turned black. I may have added fuel to the fire by putting a Tri-chlor tablet on it afterward as Tri-chlor has always been my go-to stain remover. My immediate goal is to get rid of this stain and I bought some Dry Acid to put in a sock and rub over the black spot in the hopes that might help. Please disabuse me of this notion if I am wrong.
While I'm most interested in getting rid of this black spot, we do have a larger staining problem so any help there would be appreciated.
Background
Our pool has a lot of stains. 95% of them are green and some are organic as they came directly from leaves with dirt mixed in. In recent weeks, I superchlorinated the pool hoping to get rid of the stains. It didn't do much good, possibly because the staining occurred about one and half years ago. I also tried putting a Tri-chlor tab on the stains that used to respond to a Tri-chlor tab. They no longer respond, not even after sitting on the stain for five hours. The chemistry of the plaster/stain seems to have changed.
While some of these green stains had definite organic origins, the rest are probably copper related. Their slight blueish tinge is characteristic of oxidized copper. This is not too surprising as we had a copper pipe that corroded to the point of creating major leaks.
Overall, the pool surface is kind of a mess and yet the stains are only noticeable when there is no sunshine. Otherwise, with the sun sparking on the water, our pool looks like a turquoise Caribbean paradise. I remember reading that this type of disparity can be characteristic of scaling, and we do have a high calcium hardness. However, there is no white calcium line on the tile, which I understand is typical in scaling.
Short of an acid wash or replastering, we're trying to do spot removal of the more noticeable stains.
What we've tried
What we haven't tried
Current chemistry:
FC - 5.5 (coming down from my superchorinating level of 15 or so)
CYA - 40-60 (I'm still learning how to measure this)
pH - 7.0
CH - 650-750 (note that I don't have any white calcium line on the tile so I'm not sure whether I have scaling.)
TA - I think it was around 80 or so
While I'm most interested in getting rid of this black spot, we do have a larger staining problem so any help there would be appreciated.
Background
Our pool has a lot of stains. 95% of them are green and some are organic as they came directly from leaves with dirt mixed in. In recent weeks, I superchlorinated the pool hoping to get rid of the stains. It didn't do much good, possibly because the staining occurred about one and half years ago. I also tried putting a Tri-chlor tab on the stains that used to respond to a Tri-chlor tab. They no longer respond, not even after sitting on the stain for five hours. The chemistry of the plaster/stain seems to have changed.
While some of these green stains had definite organic origins, the rest are probably copper related. Their slight blueish tinge is characteristic of oxidized copper. This is not too surprising as we had a copper pipe that corroded to the point of creating major leaks.
Overall, the pool surface is kind of a mess and yet the stains are only noticeable when there is no sunshine. Otherwise, with the sun sparking on the water, our pool looks like a turquoise Caribbean paradise. I remember reading that this type of disparity can be characteristic of scaling, and we do have a high calcium hardness. However, there is no white calcium line on the tile, which I understand is typical in scaling.
Short of an acid wash or replastering, we're trying to do spot removal of the more noticeable stains.
What we've tried
- Trichlor tablets sitting on stain - used to work after minutes or an hour, now doesn't work even after five hours
- Rubbing with Vitamin C - no effect
- Vitamin C sitting on stain - Turned a green stain black (I had thought this was one of the green organic stains, but it may have been one of the green copper stains.)
What we haven't tried
- Jack's Magic Stain ID - the reason we haven't tried is because some of the solutions (like for Copper and Scaling) probably won't work with our pool. We still have copper piping and a heater, and a simple off/on filtering system that means any concentrated Jack's chemicals in the pool will either go through all our equipment or the equipment will have to be turned off.
- Dry acid - I bought some today as I've heard that dry acid placed in a sock can sometimes work with copper. I'm hoping this will be the answer for lightening some of the green stains as well as getting rid of the black spot. Again, please tell me if I'm wrong as this is the immediate problem I'd like to solve.
Current chemistry:
FC - 5.5 (coming down from my superchorinating level of 15 or so)
CYA - 40-60 (I'm still learning how to measure this)
pH - 7.0
CH - 650-750 (note that I don't have any white calcium line on the tile so I'm not sure whether I have scaling.)
TA - I think it was around 80 or so