We have ALOT of indoor dwelling animals. Filling water bowls all day is time consuming. We have shopped for the fresh flowing commercial pet water fountains and found them to be expensive, low volume and poor quality. I came up with a high volume no frills alternative. Extremely easy to put together and very inexpensive. The critters all drink from it...large dogs to cats. The basic idea can be made to what ever fountain configuration your imagination can concieve.
Step 1: Basic equipment
One large water tight container and one smaller container. Consider the size of your smallest critter when choosing container size and height.
Smallish clean rocks to mostly fill the small container and hold the pump inplace.
One small, low volume fountain pump. A larger, high volume pump may shoot the stream on to the ceiling or across the living room.
Step 2: Fountain pump
I found this one at Menards in the garden section. It cost around $7. I do not remember the flow rate statistics. Just small. It produces a few inches high plume at the end of the tube. (next step)
Step 3: Rocks
We live in mid Michigan. Glacial till rocks are everywhere. Precleaned ones can be purchased at garden stores. Just check what is in or on them since your pets will be drinking the water that has been filtered around the rocks.
Step 4: Assembly
Stick a piece of tubing that is the right diameter for the outlet of whatever pump you have chosen. That info will be on the box. Tubing is at the hardware store. We had some just laying around that was the right diameter.
Cut the length to reach over the rocks and above the water line to what ever height is right for your application.
If the pump has little suction cups them stick it wear you want on the bottom of the smaller, rock containing container. Then surround the pump with rocks to hold it inplace.