Chlorine level 2 months after closing

[Enumjon]

Hi all. Since I had a little extra time over the holidays I figured I might as well go and test the pool. It has been closed for about 2.5 months. Has a mesh safety winter cover. Temperature is right at 32, since I had to break about 1/4 inch of ice to get to the water. At closing I raised the chlorine to SLAM level - it was at 24 the night before closing. I did not add polyquat or any other algae prevention, just chlorine. Yesterday the chlorine level was 9. It was a pleasant surprise to still have that much chlorine present. I thought that the chlorine would have all been used up with the sun and dirt that makes it through the mesh, but am happy to be wrong in that guess.

 

[cowboycasey]

I do exactly the same thing and it works... on a nice day in Jan I go out and bring the water back up to SLAM level to make sure I make it to Mar 1st and then open up

 

[Mdragger88]

@ Last years closing I did the same - about 28 ppm in late October (water below 60 degrees) then opened in April to 10ppm (water @ 60 degrees) I suspect this year will be the same. I have a solid cover though so I suspect your mesh cover allows in some organics- definitely keep a check on it periodically & open early to avoid a low fc situation

 

[Enumjon]

Great, sounds like I am on the right track. I was hoping to mix the water around a bit, but of course my sump pump appears to have just died. Since we are at 7000 feet elevation we stay cold a bit longer, but I am still planning on opening April to May - and will make sure the fc level stays in line until then.

 

[cowboycasey]

I just use the brush and do the bottom of the pool, it also moves the water and chlorine around