To do a DIY system, there are a few things that you'll have to take into consideration:
Where the deepest part of the pond is.
Total water volume of the pond.
Then if you are going to use Vertex diffusers, you can use this chart to calculate how many diffusers you will need:
![[Linked Image from i.imgur.com]](https://i.imgur.com/oxWdfcy.jpg)
You will want to have a few single membrane bubble (not necessarily Vertex) diffusers (coarser bubbles are better for winter deicing) placed approximately 30 feet out from shore for winter aeration. You will need enough to open water that is between 5% and 10% of the pond surface. Figure if you are shoving a couple of CFM through each of those membranes that they will open an area that is between 20' and 50' in diameter, depending on water depth that they are placed in, bubble size, air volume, ambient temps and snowfall. You want those placed as deep as possible, but no more than 25% of the total pond depth below the surface of the pond.
For summer use, each Vertex diffuser membrane should have (for optimum performance) between 1 and 3 CFM going through each membrane. Minimum is 1/2 CFM.
Use the lifting chart above to determine how many airstations and diffusers you will need if you are going to use Vertex diffusers. You want the total amount of water that is lifted to the surface in the summer to be between 1.15 and 2.5 times the total volume of water in the pond. If you aren't going to use Vertex diffusers, you are on your own to get the data needed to correctly design the system.
You should have a water volume measurement from the aeration company. If not, calculate how many acre feet of water is in the pond (one acre, one foot of water) 1 ac/ft = 325,851 gallons. (rough rule of thumb is 1/2 total depth x surface area = ac/ft.)
You can run both the winter diffusers and summer diffusers when the water temp is above 45-50 degrees F, but only run the winter diffusers (to de-ice part of the pond) when the water temp is below 40°F.
You have to look at the air produced by the compressors at the psi of backpressure that the diffusers will see at the bottom of the pond. Each airstation will need it's own airline, you can't "T" off of an airline underwater to run two airstations. Trust me, it won't work, even if both are the wame depth and the length of run is the same to each one. The differences in the rubber membrane of the diffusers will cause one or the other to flow more air. Figure 0.5 psi backpressure for every foot of water depth over the airstation, and figure 1/2 psi backpressure to open the Vertex diffusers. No, that is not cumulative, say if you have 4 diffusers in 10 feet of water, your compressor will need to supply between 4 and 12 cfm @ 6 psi for the system to work properly.
Gast is a company that makes a LOT of compressors, and they will make compressors for various companies to put their own label on them. Using a septic supply company will possibly get you a cheaper price.
Pay attention to the self weighted airline ID. You will need to take length of run/ID into consideration when looking at the amount of air that each airstation needs. We have run 5/8" ID weighted airline 800 feet to supply a Vertex XL5 airstation but any more than that I'd consider bumping up the ID of the line.
You will need ball valves to control the amount of air going to each airstation, a pop-off valve to protect the compressor, a low pressure gauge to help monitor how the system is running, a cabinet to protect the compressor from the elements, a cooling fan to blow cool air from outside the cabinet over the compressor, a large enough air filter for the compressor that has an element that you can change every 3-4 months, and a GFCI on the electric line feeding the compressor.
There are other things to help fine tune the system, but that should be enough to get you going.
If the compressors are in the barn, you might (depending on temp) still have to put a cooling fan on them to help lower the compressor temps. I would run a minimum of 1" poly line to the remote valve boxes on the shore of the pond, we have run 1 1/4" poly line for larger systems where there was no electric at the pond. Then transition over to the self-sink tubing for in the pond use. My advice is to NOT use the poly tube and try to weigh it down to get it to sink for in-pond use.
