How To Treat The Water??

[bsbrega]

I have an AG pool, 18K gallons. I went to a pool store for winterizing materials, and they gave me one gallon of liquid Shock It, and a gallon of Splash algaecide. I live in New England where the winters are tough. Will that do it?

[Mom2Czars]

I'm in New England too, and looking for some guidance. I believe that if you're using the BBB method, you want to clean it as well as possible, get your chlorine and other numbers (like pH) as perfect as possible. Use some Polyquat algaecide (remember, that's a type of algaecide, not a brand. doesn't matter what brand). Not sure how much, but perhaps a whole quart.

I'm hoping someone here who's knowledgeable will jump in and provide some details.

[waste]

Hi guys, good morning and Happy Labor Day! I hope I'll do for "knowledgable"
What Mom2Czars has said is correct, clean the pool, get all the chems in order add polyquat 60 (this is for insurance only - last year 2 of the Mods had slight blooms despite doing a proper closing - so splurge and use the whole quart). What wasn't said was to shock the pool (as per the best guess chart).Add the poly a day or 2 before shocking and let it mix in well. BSB, for your 18000 gal 2 gal of 12.5% shock should do it (or 5 gal 6%) as long as your cya is below 50.
I too am in New England, so I'll assume that you'll be covering the pool, the leaves are already starting to fall in Ct. For an AG pool, I recommend an air pillow (or anything else that will float and support the center of the cover, inner tubes seem to work well), teathered so that it stays in the center of the pool, it helps support the cover and push water and debris to the edges for easy removal (the pillow is not necessary for an IG pool).
Keeping the cover debris and water free is a good idea, just in case the cover falls in or rips (if that happens your work in winterizing the pool is wasted and you'll open to a mess). A small sump pump or a siphon hose can be used to keep the water on top of the cover to a minimum. To make leaf, etc removal easier they make a 'leaf rake' that has a deep net, but you can get by with your regular skimmer net.
Barring cover blow off or tearring, you should be able to open to clean, clear water that can easily be gotten to 'swimmable'.