I favor double-chamber bags. Ducks and other animals nest on ours and peck at them. If a valve pops open or our various rodents chew through one and sprout a leak, the second chamber keeps us from having an unfortunate event over the winter. The second chamber makes our pool covering more secure when we are away.

Every fall we have tried different ways to secure our above ground pool cover. So far this has worked the best. I ordered one bag per panel. We did tighten the wire cord that goes around the pool-maybe a little too much. we have some water on top of the liner when it rains. we think had we just slackened it a bit, the weight of the bags would have pulled the cover tighter and eliminated this problem. we will try that next fall. meanwhile, we only filled the bags about 3/4s to allow for freezing. we will see if they hold up when the cold weather comes.

I bought twelve of these bags and so far i have not had a problem. They definitely don't roll and that was the main reason for me purchasing them. I'm keeping my fingers crossed that they don't leak.

These are great for holding down my solar blanket all summer... I use an oversize solar blanket to hold in the heat ~ much better...! Then in winter, when I blow the plastic dome up, I use them inside to hold the flaps down. That decreases the air loss by quite a bit allowing the blower to work less... Thanks ~ Buzz (C. D. Nelson)

Work well and a good value,

Had the single chamber bags on a brick deck,spent most of the winter trying to stop them from rolling off.What a pain in the a--.Would never buy the single chamber bags again.Spend the extra money get the double chamber bags.