Three weeks ago I was posting about my swimming pool and the crew that came over to acid wash it. The crew showed up and was doing the acid wash to get the stains out. About an hour into the cleaning they decided to stop and leave. I was surprised that they left. I talked to the pool company and since they couldn't get the stains all out, they didn't want it to cost them any more time and money. They didn't charge me for what they did. It seems the stains were due to the tannin from leaves getting into pool during the winter. I found out that calcium was leeched out of the gunite finish, and where it leeched there was a very dark brown stain. The acid did lighten it up considerably. My choices were to go with it the way it was, or have a new gunite finish put on at a cost of many thousands of dollars. I decided to use it the way it turned out with the acid wash. I did another good cleaning with more acid and the power washer, then started to fill up the pool. Last night it was filled to where it normally should be and the stains look more like shadows than deep stains. The water is crystal clear. If it wasn't so cold, we could jump in anytime. Come on summer and warmer weather! I will be adding the chemicals this week and that should lighten the shadows even more.
Talking to other pool owners and the pool companies this problem is normal as a pool gets older. The good news is, outside of the light stains and the finish being a little rough, my pool is in excellent condition. It is good to have it filled with water.
While it was empty, I got a chance to measure the deep end and it measures just a tad under 10 feet deep. I always thought it was about 8 1/2 feet deep as it is shown in the original blueprints. Go figure.