Help with neighbor’s pool

[schultzjen13]

Hi! I’m not new here but haven’t posted in a while. I’ve been using the BBB method for probably over 10 years so thanks to all of you! Whenever I do have issues I can usually find help by looking at other posts on here. But now I’m at a loss and could use some help! I had noticed that my neighbor’s pool had been green for a while so I asked her if I could help. Not so surprisingly she had taken samples to the pool store and after spending hundreds of dollars she was still having issues. She has an oval shaped pool which hold 13k gallons. Sand filter.

I did learn that she used chlorine tablets so I did suspect her CYA level was going to ge high. Here were the initial readings:

Chlorine: 1.5
Ph: 8.2
Alkalinity: 150
CYA: 90!

I worked at getting the ph & alkalinity levels down and then began the SLAM process based on the suggested level which was 35 ppm. The next morning the green was gone and it became blue but very cloudy/milky.

I will mention that the method of shocking has been Cal Hypo shock because this is what she bought. I figured it was fine since it doesn’t have any CYA added.

I’ve been working on the pool since 8/12. The chlorine level fluctuates some but for the most part seems to be holding steady. But I can’t get the cloudiness to clear up. It is so milky that you can’t see very far down. This has baffled me because the chlorine level is very high. My neighbor did scrub and vacuum it yesterday and I’ve backwashed it several times. I see no signs of algae- just the milkiness.

I’d appreciate any help you all can give me!

 

[Newdude]

So you have 2 basic stages to the SLAM. First is the chemical fight where you need boatloads of chlorine to kill of the exponentially growing algae. Once it's dead/ mostly dead, it shifts to a mechanical fight to filter it all out. At this point, the FC mostly holds except for slightly elevated daily loss from the higher FC being used.

As a longtime poolstore visitor, it wouldn't be a surprise to have the filter gummed up with floccs and such. Open it up and deep clean it. If the sand is still sand like, even if it's filthy, it'll clean good as new. If it's rubbery and gummed up, it needs replacing.

Then it's just a matter of patience waiting for the filter to do its thing. Backwash at 25% psi increases and brush / vac / top off the FC while you wait it out.

 

[mknauss]

Cal Hypo will also cloud the water. Switch to liquid chlorine.

 

[schultzjen13]

Thanks for the help! The pool is looking much better!

 

[Brian PacNW]

Thanks for the help! The pool is looking much better!

Was the filter medium nasty?