How often should sand in a sand filter be replaced?

[skywalk1962]

PH is 6.8 chl is 2.5 kinda green in color have put in algecide and clarifier.

[PoolDoc]

+ Forget about the algaecide and clarifier
+ Add 2 gallons of BLEACH per 10,000 gallons in the PM.
+ Add one box of 20 Mule Team borax, per 10,000 gallons per day, till your pH is above 7.2
+ Test daily BEFORE adding bleach with a cheap OTO / phenol red test kit.
+ Report results here.

+ Continue to add bleach daily unless pre-bleach evening test shows "orange" OTO levels
+ Use strips or have pool store test your water to determine stabilizer levels.

+ Do NOT add goop: clarifiers, enzymes, phosphate removers, etc.
+ Do NOT 'balance' (increase alkalinity or calcium or adjust pH) except as per borax above.
+ Do NOT let chlorine get low, ESPECIALLY while your pool is green.

+ Once your pool is bluish, TEST your filter by adding a small amount of DE powder (pool store, maybe). If the DE returns into the pool (as a cloud from the pool returns, your filter needs work. If not, it is functioning more or less.

**** NOTE: Mods, others, this is using DE for TESTING, not for filter enhancement. The point here is to see if the filter *****
************************** is working, not to improve algae removal. ****************************************

Ben