OK so the plot thickens..The stain has returned in the shallow area,,keeping the CL low (around 2) and adding a bit of polquat...been trying to boost the CL by adding more cal hypo daily (2 - 3 scoops x2 daily) CL has been up to 5 last two days but now the water pool has gotten cloudy and turning green.

Readings as of today from the pool store:
CYA - 28
Tot. CL - 7.5
FC - 6.6
pH - 7.3
Tot. Alk - 110
Adj. Tot. Alk - 102
Copper - .2