i have made sveral fluid beds and the aquaium pumps are actually more air than you need. on certain colors i have to turn the air down so they are not blowing out of the cups, the membrane in the bottom of your cup is what determines how much air is getting thru. it cost me $35 to make the whole thing but i got a pc of the membrane for my cups from a chemical company here in town. the fluid membrane is expensive but it works awesome