Discolored, pitted plaster pics
- Thread starter nexx2
- Start date
Late getting home from work. Will post pics tomorrow evening. The pitting and discoloration started a couple of years ago. Just want to understand what could have caused this.
Post a set of your current pool test results with the pic(s) It may give some extra insight. I think we can solve it for you but it won't be a "magic" fix.....it'll take some time.
Test results per Duraleigh.FC4.5 ppm (I will be putting in the nightly dose after this with target of 8.00ppm)
CC .5ppm
pH 7.8
TA 80ppm (2 weeks ago the result was 130ppm. Maybe an error on one of the tests?)
CH 200ppm
Pool was replastered in 2007. About 3 years ago pool was diagnosed with black algae. Was told by pool store to put in enough kill for 16,000 gallons and pool is actually 10,000. Rub every spot with chlorine puck and wire brush tough areas. I don't know when the pitting first started, but I believe it was after the algae problem. It wasn't very noticeable because everything was still white, but as the plaster became 2 tone and splotchy it became very noticeable. When I would take pictures of the pool it would not show up much. A few weeks ago I drained the pool down because of cya high and took pics of pool wall and it was obvious. I traveled alot and depended upon others to take water to pool store to be tested and add chemicals. So maybe a combination of things? I have only been using the TFP system for about 3 weeks. I would think there is no fix other than replaster down the road, but hoping diagnosing will help me and others not have this happen again. I can only download 1 pic because of size. Will have to figure out how to decrease size.
This evening test results:
FC 6.0
ph 7.5
CH 220ppm
I am now a supporter and waiting for confirmation so I can upload more pics.
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Does it seem more pitted? Or are the darker areas rough and raised? Two main plaster problems are etching and scaling. Etching causes pitting in the plaster surface due to low PH and low CH and the plaster releases CH into the water l3aving pits. Scaling causes a build up of calcium on the plawter as calcium is deposited from the water onto the plaster and occurs in high PH, TA and CH scenarios.
The darker areas are a little smoother than the white on the side walls and bottom. The seats and steps are mostly white and rougher. Whatever caused it sounds like it was a chemical problem, too much or lack of. Is it possible to make all the plaster white again with high levels of bleach or other?
If it is etched then no, nothing can be done. If it is scale then yes, it is possible to remove the scale from the plaster.
Acid will dissolve scale. You can out some dry acid in a sock and rub it on an area for 5 or 10 minutes. Or you can apply some muriatic acid directly on an area with a squirt bottle and brush it.
There are a few options from there if it is scale.
More here also, Pool School - Calcium Scaling
There are a few options from there if it is scale.
More here also, Pool School - Calcium Scaling
Using the squirt bottle with muriatic acid and brush, I would need to drain some water to get to a scaled area above the water line?
