Hello again !
Hope I'm not being a pest! Several things discovered today may be of interest to other pool owners.
The eyebolts that the safety rope attaches to were chrome plated .The chrome eventually has worn off leaving the base metal . The base metal is brass . I can see some corrosion on them (I removed them today). just wondering if this is the source of the metal in the water. Brass is a mixture of copper and zink. I realize the water balance is still the cause to erode the chrome off the eyes and then attack the brass. mwb
On another note , the step that I cleaned this morning with Vit C is starting to stain again this afternoon.
At this time it's a nice sunny day and my daughter is coming over. The ribs are on the grill and I'm on my third margarita. This father is going in the pool!