Beautiful day here so I decided to test my water for the 1st time this season. The pool is still covered.
My 1st question is at what temp would algae start growing?
Scheduled to have opening May 6th but concerned now that see my chlorine levels. I don't think I should add chlorine without the filter running.

I also have a heater, is there a specific Alk target I should shoot for?

Does Calcium affect the heater at all?

30X20 15X32 IG vinyl straight "L" about 50K gallons

Temp: Cold less than 50 degrees
FC: 0
CC:0
TC: 0
PH 7.2
Alk:60
Cal:70
CYA: less than 20