Hi, I have been using the BBB method for the last two summers and overall it's done a good job of keeping algae away. I have been using a combination of bleach and triclor tablets for chlorination. However, I have always had a problem with yellow/green staining of the entire plaster surface of the IG pool. Vitamin C tablets on the stain makes it go away locally. I did the procedure mentioned here on TFP involving a few pounds of vitamin C powder, and it worked at first...but the stain just reappeared over the coming weeks. Even with liberal use of sequestrant. This has been very frustrating, and am at the point of draining the pool and hiring someone to acid wash and take care of it.
As of today, coming out of the winter here in San Diego, here are my numbers:
CYA: >100, maybe 150
Copper: The test strips were mostly useless but seemed to indicate I have less than 1ppm of copper
Pool: 15k gal IG plaster, DE filter, water is 2yrs old
Any suggestions on how to get rid of the stain and more importantly keep it from coming back? I am considering draining the pool to get the CYA, CH, and TDS numbers down, but I don't want to go through that expense unless it will help with my staining problem.
Here is a pic that shows what I mean. It is looking down into the water at my step. You will see a yellowish/greenish stain that is the bane of my existence.
Thanks for anything you are able to suggest to help!