Help! Cloudy blue pool will not clear up!!

[Froggypool]

My pool has been cloudy for 3 weeks. Ever since I opened it. I have a 5 year old AG 30 ft (20,0000 gal) pool with a 1.5 hp Hayward pump. I have a 250 lb 18 in. Sand filter. I have been using the BBB method for 2 years. This year I cannot get the cloudiness to go away. I have been trying to keep the chlorine level at 15 ppm for the last 4 days to kill algae. I have also completely changed the sand in my filter yesterday. Here are my numbers, thy have been running pretty consistent for the past week or 2.

As of this morning:

FC 10 (just added 7 ppm this morning to boost)
CC 0.5
TA 150
Ph 7.4
Calc hardness 70
CYA 55

 

[Butterfly]

You should follow the SLAM level in Pool School to a T !

What test kit are you using?

Changing the sand was more than likely unnecessary

FC SLAM level for CYA of 55 is about 22 .

Welcome to the forum

 

[Richard320]

Welcome!

SLAM it at 22 FC like Butterfly says. Adding some DE or cellulose to your sand filter as mentioned at the bottom of the SLAM article might also clear things up sooner.