Hi Anna -

Wow - great info.

I suppose I should have given pool stats to start - I'm sorry about that.

I have a 24' AG (13.5+K gals) with a vinyl liner. I utilize a sand filter with DE in it (in addition to sand, not instead of).

The water is clear with no color whatsoever (other than staining on the liner from iron issue we started with).

The tests that had the color variations were TA and CA. Red vs. Magenta and indigo/purple vs. blue. More drops did not change it.

I did CYA twice here today the first was 40 (couldn't see dot at all); second was 50 (could see dot if you really tried).

I haven't used pucks in 3 days. I used cal hypo today to shock (pool store said I had 5 ppm iron - so I shocked to shake them out of hiding in order to filter them out). Prior to that was bleach, while we filtered iron (homemade filter and DE - worked magically).