Details on Closing my Pool

[Mherndon68]

I read the article on closing an above ground pool and I have just a couple questions.

First it’s a 24’ semi in-ground using a SWG. Couple days ago I tested the water myself and got a reading of 18 ppm. We hadn’t been using it for a while so the solar cover hadn’t been off and I never turned down the swg because I expected it to make less chlorine. Anyway I took a sample in to confirm my reading wasn’t an error and yep it’s high. She said I want it down to about 4 ppm. That seems a little low. The article says chlorine at shock levels, so what are shock levels for over the winter? I see I can use an algaecide but I’ve never needed it and if I can get away with it I’d rather just use the chlorine levels, a cover to block out sunlight, and the cold temps to prevent algae until spring start-up.

I’m also curious on the sand filter. I didn’t empty it last year just took out the drain and took the valve off, drained the pump and disconnected and drained all the plumbing. Then covered up the pump and filter. About mid winter I got worried that maybe the sand retained moisture and I was going to find the sand filter split open. Is draining the sand enough or did I just get lucky. Do I need to add in some type of antifreeze and flush it out in the spring?

Many thanks
Mark

 

[mknauss]

Welcome to the forum.
What is your CYA level? Article says raise the FC to SLAM Level for your CYA (that is what they mean by 'shock' level).

Draining the sand filter should be sufficient.

 

[Mdragger88]

As Marty mentioned the correct slam level depends on your cya level
See—>> FC/CYA Levels
4ppm is not slam/shock level for any cya level & is definitely low

 

[Mherndon68]

My CYA level is really low <30. The calculator in the FC/CYA levels above says 30 CYA needs FC 4-6 and a minimum of 2 but those are the maintenance levels aren’t they. Is there a calculator for Slam/Shock levels? I wasn’t going to worry about the CYA until spring since I’ll cover as soon as I get the FC where it needs to be. Should I increase my CYA before closing too? If I’m understanding the CYA/FC relation I’ll need less FC with a lower CYA.

 

[Mherndon68]

My CYA level is really low <30. The calculator in the FC/CYA levels above says 30 CYA needs FC 4-6 and a minimum of 2 but those are the maintenance levels aren’t they. Is there a calculator for Slam/Shock levels? I wasn’t going to worry about the CYA until spring since I’ll cover as soon as I get the FC where it needs to be. Should I increase my CYA before closing too? If I’m understanding the CYA/FC relation I’ll need less FC with a lower CYA.

Found it in the calculator I just had to back up a step and choose slam. Thanks

 

[Mdragger88]

The only issue with below 30ppm cya is that it’s unreadable on the test. You may have between 20 & 30 which counts as 30ppm for chlorination purposes. So 12ppm slam level vs 10ppm for cya of 20 or less. I would just go with 12ppm. Be sure to do an Overnight Chlorine Loss Test to confirm you’re algae free before buttoning it up!