Could it be my filter?

[ArkieFlyGuy]

Sand filter
20,000 gal pool
FC 24
CC. 0
CYA 40
pH 7.7
TA90

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?

 

[duraleigh]

still getting green residue on the bottom and sides

Green = live algae. Use chlorine to kill algae.

Brush it up, stir it up, get it mixed into that chlorine laden water. Your filter will not kill it, it can only filter out the dead stuff

 

[ArkieFlyGuy]

OK... Brought TC up to 24, brushed and stirred it like a big bowl of stew. Leaving town on business until next Friday. Crossing my fingers my better half can keep up the pace...

 

[257WbyMag]

The better job you do of keeping the FC at shock level, the quicker your algae issue will be corrected.

 

[ArkieFlyGuy]

Got home Friday and not much improvement, but at least the better half kept things from getting worse. Back to keeping TC uo around 17/19 and brushing.