Cloudy water after SLAM

[Boko]

My pool was in bad shape this year. Pea-soup green when I opened it, tons of leaves on the bottom. I SLAMed it for about a week, scooped out the leaves, and (I believe) killed all the algae.

The water turned from dark green to a cloudy gray/white color and I couldn't see more than a few inches into it. When I started, I had to backwash the sand filter multiple times per day. Now the water is flowing through my filter and pump well, with a 1 PSI daily increase, which is much better.

My problem is, it's been over a week of constant filtering and the pool is still very cloudy. I can only see about 1.5 feet into it. I have a sand filter and a 1HP Hayward Powerflo Matrix pump. The pool is about 12K gallons (16 x 32 oval above ground).

I’ve been keeping the FC high out of paranoia that something’s still alive in there. Last night it passed the overnight FC loss test with CC somewhere between .5 and 1, so I’ll probably let it drop down to normal levels.

I'm wondering if I need to be more patient and wait for the cloudiness to clear up, because it does seem to be very slowly improving. But at this rate it will be time to close for winter before I can get into it! Maybe I backwashed too much and lost some sand? Maybe I need to replace my sand?

My kids are getting impatient too. Is it safe to enter a cloudy pool if the FC is in normal range and it passes the overnight FC loss test?

Here are my current numbers. I recently got the Taylor K-2006 test kit.

FC 22
CC <1
PH 7.6
TA 120
CYA 35

And advice would be greatly appreciated. I love this site! So much great info and helpful people here.

Thanks.

 

[Azgirl71]

Welcome to TFP!
You have passed 2 of 3 criteria to pass SLAM. You have to pass the 3rd. Clear water before stopping SLAM. You are doing great though. Bring FC back up to SLAM level until water is clear.

- - - Updated - - -

PH won't read correctly above 10 FC

 

[Richard320]

You're not done with the SLAM yet. Anything you can do to improve circulation and filtering will speed things along. If you can aim the return jet, point it down to stir up the sediment where the skimmer can catch it. Or connect a vacuum to the skimmer and set it on its side down on the floor so you're drawing water from down deep where the stuff wants to settle.

You might also consider adding diatomaceous earth or cellulose filter media to your filter as mentioned near the end of the SLAM how-to. It forms a fine layer on top of the sand that filters finer particles. Sort of like setting window screen atop chicken wire, just on a microscopic scale. You'll want to be home to keep an eye on the filter pressure when you do that. It won't take much - see if you can;t beg a margarine tub's worth from a neighbor with a DE filter. Pool School - Add DE to a Sand Filter

 

[Boko]

Thank you both for the advice. I thought my SLAM might be done and the only thing left was to clear the cloudy debris. I'll keep it going until it's truly clear and try adding a little DE to speed it up.

On a positive note, I just realized I'm able to barely make out the bottom of the pool when I shut the pump and the water becomes still. That's a huge improvement from a few days ago. I might be able to swim this summer after all!

 

[Boko]

I want to thank you for advising me to add a little DE to my sand filter. 2 days of running with DE has cleared my cloudy water better than 10 days without it! You've salvaged my summer! Thanks!