20,000 gal pool
Shock, vacuum, backwash, repeat. Been doing this for a couple of weeks and still getting green residue on the bottom and sides. Went to a higher FC shock - 15 up to 20/24 - thinking maybe it's mustard algae... How do you tell?
Now I'm beginning to question my filter since the pool gets cloudy after vacuuming manually or with the APC. Crossing my fingers it's channelling but how do I tell if I just need to change to new sand?
Any recommendations on sand replacement both product and process?