Moving water with a homemade airlift vs. a pump - 09/01/14 12:47 PM
Although not specifically about ponds, the following does involve raising fish, albeit with a fish tank in conjunction with a separate raft tank of tomatoes, peppers, lettuce, and spinach. The electrical cost is cut in half by using all air and NO water pump. If I was to use a biofilter that does not require air, that is gravity fed, such as an rbc, the wattage would be cut at least another third.
As you can see the airlift does not sit in a vessel of water but is external vs. the typical airlift that is mounted in a vessel of water. It receives water via gravity up to the same level of the vessel it came out of (in this case it's a a moving bed filter), and the air pushes it the rest of the way out. (I hadn't trimmed the upper portion yet.)
Here is the 1.5 inch vertical riser pipe that terminates just below the water level of the raft culture tank.
I actually dug a trench to drop the level of the riser pipe as close to the optimum 65 inches as possible. Unfortunately I wasn't able to go the full 65 inches as I hit a drainage pipe of all places right in line where I set up my connection to the raft tank! I will however be increasing the size to 2 inches to increase flow, and will move it over a little out of the way and under the buried pipe and will be able to set it at the optimum 65 inches. Next year!
Part of the trench that shows the fitting and airline that was tapped in.
The pressure chamber is two 2 by 1.5 inch reducers glued together with 3 rows of holes drilled into the 1.5 inch pvc pipe that slides through these pieces to create a chamber. I had to do some grinding on the fittings to get the 1.5 inch pipe to slide through. Once the two reducers are slid over the holes, it's glued in place. This is know as a yamabuki pressure chamber airlift design. The Europeans are moving about 66 gpm of water with zero lift on only 10 watts of elecricity with a 20 lpm pump for their high end koi ponds.
The left barrel is the clarifier tank that is packed with orchard netting that traps solids via siphon tube from the fish tank. The water overflows to the right barrel that is the moving bed biofilter. All gravity no pump required to move the water from the fish tank until the airlft takes over.
The water exits the bottom of the moving bed barrel (one on the right) and fills up to the same level as the moving bed barrel (no head as it is the same level as the barrel when it exits the vertical rise pipe). The mb3 media is kept in via a shower drain installed in the 3 inch exit pipe.
Water flows via gravity back to the fish tank (fish tank is lower than the raft tank)
The air pump mounted in a weather proof ventilated box that feeds the system.
80 lpm (60 watts) air pump is enough to run the airlift, fish tank membrane diffuser and moving bed barrel. 600 + gph with a 1.5 inch airlift. Should be able to move more once the airlift height is optimum and the diameter of the riser pipe is increased. There is also considerable water resistance in the raft tank due to extensive plant roots, and flow was measured at the tank return. So flow is probably greater at the raft tank inflow.
Reduced diameter of riser pipe ='s more lift
Increased diameter of the riser pipe ='s more flow.
As you can see the airlift does not sit in a vessel of water but is external vs. the typical airlift that is mounted in a vessel of water. It receives water via gravity up to the same level of the vessel it came out of (in this case it's a a moving bed filter), and the air pushes it the rest of the way out. (I hadn't trimmed the upper portion yet.)
Here is the 1.5 inch vertical riser pipe that terminates just below the water level of the raft culture tank.
I actually dug a trench to drop the level of the riser pipe as close to the optimum 65 inches as possible. Unfortunately I wasn't able to go the full 65 inches as I hit a drainage pipe of all places right in line where I set up my connection to the raft tank! I will however be increasing the size to 2 inches to increase flow, and will move it over a little out of the way and under the buried pipe and will be able to set it at the optimum 65 inches. Next year!
Part of the trench that shows the fitting and airline that was tapped in.
The pressure chamber is two 2 by 1.5 inch reducers glued together with 3 rows of holes drilled into the 1.5 inch pvc pipe that slides through these pieces to create a chamber. I had to do some grinding on the fittings to get the 1.5 inch pipe to slide through. Once the two reducers are slid over the holes, it's glued in place. This is know as a yamabuki pressure chamber airlift design. The Europeans are moving about 66 gpm of water with zero lift on only 10 watts of elecricity with a 20 lpm pump for their high end koi ponds.
The left barrel is the clarifier tank that is packed with orchard netting that traps solids via siphon tube from the fish tank. The water overflows to the right barrel that is the moving bed biofilter. All gravity no pump required to move the water from the fish tank until the airlft takes over.
The water exits the bottom of the moving bed barrel (one on the right) and fills up to the same level as the moving bed barrel (no head as it is the same level as the barrel when it exits the vertical rise pipe). The mb3 media is kept in via a shower drain installed in the 3 inch exit pipe.
Water flows via gravity back to the fish tank (fish tank is lower than the raft tank)
The air pump mounted in a weather proof ventilated box that feeds the system.
80 lpm (60 watts) air pump is enough to run the airlift, fish tank membrane diffuser and moving bed barrel. 600 + gph with a 1.5 inch airlift. Should be able to move more once the airlift height is optimum and the diameter of the riser pipe is increased. There is also considerable water resistance in the raft tank due to extensive plant roots, and flow was measured at the tank return. So flow is probably greater at the raft tank inflow.
Reduced diameter of riser pipe ='s more lift
Increased diameter of the riser pipe ='s more flow.
