Pond Boss Forums AERATION Systems questions Selecting Pump for Aeration. Does This Seem Right?

A few comments. Good start and here are some ideas for those reading this and thinking of building a similar system.
1. An adjustable pressure relief valve would be more helpful. I have those for 1 -30 psi 3/8" threaded.
2. Diffusers. A better tubing would have been the vinyl tubing 1/2" ID. Your methods makes an actual roundish hole due to the hard tubing and IMO makes too big of bubbles. Punching the vinyl tubing or a garden hose results in more of a tiny slit shape. Slit shapes produce finer/smaller bubbles thus allowing more bubbles to be produced per cfm of air. Rule for homemade diffuser. The smaller the bubble the more water you moved per cfm. Slits are actually better than holes because slits tend to produce a smaller bubble and you can have more of them compared to a larger hole. The needle could make a slit in soft tubing if the needle was ground into a flat blade. A small finishing nail with the end flattened and ground to sharp edges makes a good slit. I used this as a "needle" when we made coiled tubing diffusers. Put the "needle" in a heavy duty sewing machine and punched a few rows the vinyl tubing of required lengths usu 10 to 20ft for the coils. The benefit to your method is the larger holes will not clog as quickly as slits but significantly fewer bubbles are produced thus moving less water per hr of operation.

3. I would have placed the tubing in a coiled pattern similar to a burner on an electric stove. This would produce a 10" to 15" dia circle that was completely filled with bubbles - rim to center similar to that of a disk membrane diffuser. Small punched holes would allow longer tubing to disperse the bubbles filling the complete circle with rising bubbles. Your current design produces bubbles only on the rim that tends to not move as much water due to the central area not filled with bubbles. Best circular diffusers completely fill the circle with bubbles.

4. IMO you should have low psi backflow opening check valve on the diffuser. All good diffusers have check valves either built in or added ons. Vertex membrane diffusers have a special air distribution valve and it causes a small psi back pressure. I prefer ck.valves without springs thus minimal back pressure at the pump.

With your current system, when you shut off the pump,,, everything under water fills with water. Then when the pump restarts it has to push all the water out of the airlines before it can produce bubbles. This is very hard on and over works the compressor thus shortening its life span. You can determine when the water is out of the airline by watching the pressure gauge. At pump start up with water in airline, gauge will go to full psi and psi relief works until bubbles are released and then psi will drop back to operating psi. Note bubbles rise at about 1 ft/sec. Thus at 10 ft deep bubbles are seen at the surface abt 10 sec after they are produced. If you try to run this aerator in winter and stop the compressor or ANY reason (electric outage, etc), the water filled airline at the surface will form an ice plug as thick as the ice.
5. You can check if you have enough holes in your diffuser to release all the air that the pump produces. If you are not releasing all the air the pump produces,, it will result in added unnecessary back pressure on the pump. Checking if diffuser releases all the air - Hook up, with a only short hose from pump to one diffuser with an air gauge in-between. In your case, use a very short hose from one valve to diffuser. Turn off all valves except one with diffuser attached. Turn on the pump if you don't have enough holes psi back pressure will show on the gauge. When diffuser is getting rid of all the air psi will be 0. Keep adding holes until gauge reads 0, thus releasing all the air. Note - very small and too tight of holes on diffuser, even when you have enough holes, will cause some back pressure on the pump.