Need a big pump to move water or air? It's not too hard to make your own with PVC pipe.
The video above should give you a great idea of how to tackle this project, and the source link has more details if you need it. The build is pretty much all PVC parts, plus some rubber O-rings and petroleum jelly to create an air-tight seal within the tube.
The biggest prerequisite is a couple of one-way check valves that King Of Random previously showed viewers how to build. Luckily, these are pretty cheap to make too, and shouldn't take you very long. Once you're done, you should be able to move as much as five gallons of water per minute through the pump, or enough air to flood any birthday party with balloons.