Minnidip pools are made with heavyweight vinyl so they will be stiff out of the box, especially when the air temperature is cool. The longer they’re out of the box, the more pliable the vinyl will become. We recommend filling the pool up with as much air as possible, closing the valves but not tucking them in yet. Then stretch the rings to form it into a circle so air can get in the creases. Then let it sit for a bit (in the sun or warmer temps, the vinyl will warm up and the air inside will expand) and then add more air through the one-way air valve using your mouth. A few big puffs of air using your mouth will have more power than a pump, so you’ll be able to get it nice and firm by finishing filling it up using your mouth. Then close the valves completely and tuck into the pool