Help - Green clear water

[masspool]

Hi All:

UPDATE

It rained hard today here in Central Massachusetts (the rain is obviously acidic here)

It has been cold the last week or so (32 degrees at night to 55 as a high during the day).... the pool is not heated so the water is very cold.

I came home from work to find that, during the day, the pool has turned from Lime green to blue.

This is strange....don't know whether all of the metal-control chemicals finally kicked in? Or, something else changed (the PH and chlorine both did decrease from yesterday) Or was there something else at work here ?

using a Taylor K2006 test kit, I recorded the following readings:
FC=5.0
CC=0.5 (so TC is 4.5)
-
PH=7.0
TA= 40
CYA = 35 (halfway between 30 and 40)

Anyway, I suppose I should bring up the PH a little (to 7.2 or so) ?

BTW: The pucks are still in my in-line chlorine feeder - and I have not shocked the pool since Saturday - nor have I added any chlorine since saturday (no bleach, no powder) other than via the feeder