Restarting pool

[Quant]

I have been following TFP wisdom for some years now. This year I let my pool slip and go green--no chunks but the water was very colorful. The visible organics were gone instantly but I kept it slammed til it looked clear and passed the overnight test. The problem is, it took like 4 days of continuous pump flow to go from very milky/white to crystal clear. My questions:

1. How long should it take a sand filter to clear a 20k pool from dark green (but no solid algae chunks). I am sure the motor is sized and functioning, but could I be low on sand?
2. What do you think about shocking, but not running the continuous slam and overnight test until the water is no longer milky/cloudy? It is a lot of chlorine to keep the levels up over 4 days in the AZ sun.

Thanks!

 

[Texas Splash]

How long should it take a sand filter to clear a 20k pool from dark green (but no solid algae chunks).

Varies from pool to pool. Owner consistency to the SLAM Process and chemistry in the pool itself make SLAM times vary. Many SLAMs easily take several days to a week or more.

could I be low on sand?

The only way to know for sure it to open it up.

What do you think about shocking, but not running the continuous slam and overnight test until the water is no longer milky/cloudy? It is a lot of chlorine to keep the levels up over 4 days in the AZ sun.

Sporadic shocking is just about worthless. Owners are either doing a SLAM or not. Maintaining the elevated SLAM FC level is key.

But your post is confusing. You said above "I kept it slammed til it looked clear and passed the overnight test.", but then later say "What do you think about shocking, but not running the continuous slam and overnight test until the water is no longer milky/cloudy?". If you passed all 3 SLAM criteria, there should be no need to shock or elevate the FC anymore.