Man you guys must have some short tanks to get playsand being pulled up into the intake on a AC... I have 2 AC 50's on a 10 gallon with playsand in it... (Feeder tank) Both filters are turned down to almost the min setting but I've never even seen a single grian of sand float anywhere.... when i turn them up the sand gets blown all over the place from the output...but then I also get comets being sucked into the intakes LMAO So I tend to keep it turned down ....