still have green pool

[gregugadawg]

Just curious but why did you go from a D.E. filter to a sand filter? This is going to make the cleanup process a lot more time consuming and tedious

[cschnurr]

Brushing the bottom will help mix the algae up so it can be attacked more evenly by the chlorine and picked up throught the skimmer.

But vacuuming the bottom might help to remove the dead algae as its killed off.

[Watermom]

Vac to waste and not to your filter.

[brent.roberts]

Save the polyquot until the mess is cleaned up and chlorine levels are stabilized.

Even then you may not need it ( other than a double dose for winterizing ). Lots of folks here do not us any algecide. Proper chlorination will do all that is needed to control algae and other contaminants. Having said that there are well experienced folks here that use polyquot as a preventative. Sort of like using a belt and suspenders. Suit yourself. But don't waste it now. You'll be vacuuming and dumping a lot of water and your polyquot with it.

When I got my pool along with the house we bought, it had about the same level of CYA as your 120. Had to dump almost half the water twice to get it to 40. Until I did that I had the tablet auto chlorinator going flat out to try to stop the algae blooms. All the time it was add more and more CYA and making it harder to keep enough chlorine to prevent the algea ... the previous owner had been doing that for years. Bleached the h*** out of the liner in the process. He also poured 3 or 4 carboys of pool store chlorine in at a time. He really shmucked it.

Anyway ...now down to about 40 CYA and using nothing but bleach for a year without a problem.

You'll get there. Good luck.