Richard

Do you think the white crust, etched Spas tiles and black algae had anthing to do with adding too much CYA at one time? I added 8lbs one day and another 8lbs the next. I was going to add another but stopped when I noticed the white crust and black algae.

If so do you have any suggestions as to how to add large ammounts of CYA without getting the damage or black algae?

On Cl level the Install and Ops guide from the Mfg of the CL Generator http://www.jandy-downloads.com/pdfs/H05675-RevE.pdf on page 18 says "Free Chlorine 1.0 - 3.0 PPM. Above 3.0 PPM may cause corrosion of
pool metals." Is this just more bad information from the Mfg? On the same page above "The AquaPure is warranted to operate properly
only if these conditions are met." Seems like a catch22?