What Size Pillow(s)

I have an 18'X33' with a 52" wall, What size and how many pillows will I need when I go to close it it the fall.

Up here pool stores stopped selling them because of their "useless" factor, and if a poolstore is going to not sell you something because it's useless, it MUST be REALLY true since most stuff tehy try to sell you over the summer is 90% useless.

So Matt, do you cover yours with nothing in there to absorb the expansion? Just shock, drain, put on the winter cover and nothing else? We didn't know if we should buy a pillow or throw in an inner tube or what........

The liner places a barrier that goes through the ice, it goes down into the water and rises above the water, so you never actually have a true formation of ice accross the pool, if it expands then the ice on top of the liner will rise thus relieving the pressure on the sides of the pool.

This is my theory now, and no way backed up by anything or anyone, just something I have thought about and concluded upon myslef.

I don't have the ice issues that some of you have. However, I always cover my 18' x 36' ag pool to keep the many leaves from the five oak trees that are over or around my pool from ending up on the pool bottom.

I've always put in pillows to minimize the "oceans" that form on top of the cover from rains. I've tried all kinds of sizes and combinations of pillows over 4 seasons, and each season I use less pillows - I believe next year I'm going to go with a single 4' x 15' pillow across the width of the pool in the center - that would be my recommendation.

I don't cover my pool - period.
I shock, drop the level - why? - I really don't know, because rain and snow just fills it again!

Your ice theory is good Sevver, however, if the pool freezes solid, theory becomes nul and void. Up here, pools freeze solid - AG pools anyways.
Here's what really happens when they freeze - ice will expand - no doubt about that, however, it will expand in the direction of least resistance first - meaning up/down.
When my pool frezzes partially (1 foot), there is a gap between the wall and ice about 1/4" thick through which I can force water up if pushing on the ice, likely due to friction. If it freezes solid, the gap is still there, however, no water - makes sense - it's frozen solid.
If you put a plastic water bottle standing up in the freezer with 2" air at the top, the bottle will not stretch around the perimeter, however, the 2" air gap on top gets reduced to a smaller space.

Pillows are supposed to keep the water off your cover by lifting it, they are not in there to absorb expansion, if they were, they would have to be submersed from bottom of pool to surface of pool, floating them on top does nothing to help absorb expansion. Lifting the cover and running the water off is supposed to alleviate streeses to the structure on AG pools (like walls pulling in - the #1 cause of Pool collapse in Canada), and keep covers from pulling out from under the weights on IG pools and sinking into the pool. However, if you place a couple of pillows on your pool, it will only make the water move to a different location on the cover, so the pillows really don't do anything.
The only way to remove water completely off the cover would be to build a roof support structure under the cover similar to a pool greenhouse - I don't think anyone would want to go through that trouble.

I saw an add once for something that created a tepee effect. You set up this pole in the center of the pool(it had a wide round base) and tied down several straps to the side. Then you put the winter cover on. Everything runs straight off the cover to the ground. Unfortunately, the item was discontinued. Seemed like a good idea.

I'm sure you could make something similar with PVC pipe to do the "tent" effect.

We will, unfortunately, have real issues with leaves if we don't cover the pool. how do we do that without the worry of water/ice build up on the cover?

I lieve in the NE where the pool doez freeze and my pool store reccomends at lease on pillow. I have a 24 AG pool and use a 4'x4' pillow and have never had a problem. I do secure it so it wont move around. I might go bigger this your, just a piece of mind thing for me.
John