You guys are getting a little technical here, then assuming a the worst. There are different levels of DIYers. This one, asked similar questions years ago. Here's some of what I came up with, hope you can appreciate it.
The job starts with the Goal, in this case - get air to the bottom of the pond. Let's not over complicate.
The Aerator has two jobs. 1. Inject some air, via tiny bubbles. 2. Create a current of water.
Both Vertex and Matala are so similar in both. Visually, Matala looks more impressive with less air.
I already said, I'm running 3 diffusers at 7 feet depth, with just under 4psi back pressure at the pump.
What we know from the manufacturers;
Vertex XL2 data shows, 2,400gpm at 7 feet with 1 cfm.
HiBlow 120LL data shows, 3.8psi = 3.4cfm.
HiBlow should be able to run 3 diffusers nicely at 7feet depth with 1cfm each. And it appears it is.
How do I confirm the actual current flow? I did this years ago.
Paddle out over the Matala boil of bubbles and measure the boil diameter, it's about 30", but it starts out at 12". I estimate a 24" diameter column of water average for this purpose.
Next figure out how fast it is rising. See how deep I can let go a bright nylon ribbon into the column, before it rises to the surface in 1 second. It's just over 2 feet.
Calculate the 24" diameter by the 24" depth, it's approximately 47 gallons of water, per second.
So, 47 gallons per second x 60 seconds is 2,820gpm. This is really close to the Vertex claim of 2,400gpm. I'll round down to Vertex numbers going forward.
How long does it take to turn over the volume of water in the entire pond?
Calculating the pond size of 1.2 acres with an average depth 6 feet, 2,376,000 gallons is estimated.
2,400gpm x 3 diffusers = 7,200gpm x 60 minutes = 432,000 gallons per hour. This means the pond turns over once approximately every 5 1/2 hours. A number I'm very happy with.
