Still have Cloudy Water

[Geojaneo]

2nd year user @ TFP - opened SW pool on 5/10/17 to green water.

Initial tests:

FC 0
CC 0
CYA 65
PH 7.2
TA 60

Followed SLAM procedures and after passing OCLT test, CYA was 50 on 5/13 so added 56 oz of stabilizer. CYA has remained at 65 since 5/16.

This a.m. readings (after 2.8 inches of rain and a backwash)

FC 14
CC 0
TC 14
CYA 65
PH 7.2
TA 90

Sand filter has never been cleaned (9 year old system) - during last 10 days added DE a few times following instructions - backwashed twice as pressure rose. Hubby has now modified filter fittings so sand can be cleaned. Water remains slightly cloudy.

Questions:

Do we clean sand filter before adding any more stabilizer to CYA?

Do I raise CYA to 75 since reading is subjective and may be closer to 70 than 65?

Is it harmful to add any more DE to skimmer? If not, can I do at same time as CYA since filter needs to be run for 24 hours?

Thanks much TFP

 

[spinPHD]

Since your trying to clear up your pool, I wouldn't add any DE to your sand filter until after you get all your chemicals balanced and pool clear. The reason being is you are backwashing a lot right now to get pool clear, and you just end up losing the DE each time. DE in sand filter is best used to make a clear pool clearer.

 

[pooldv]

As long as you add CYA in a sock or knee high as shown here, Pool School - Recommended Pool Chemicals, it doesn't matter what you do with your filter. Might as well backwash first though.

You'll want your CYA up to 80 by the time summer gets here.

Here is how to add DE to a sand filter, Pool School - Add DE to a Sand Filter I don't think more is better.