The 1/2 Inch Rule
Most pond fountain manufacturers recommend that you have an outlet diameter of at least 1/2 inch for each acre of pond surface area.
Now, if you’re on a tight budget, you can get away with a bit less than that, but if you’re really serious about keeping your pond healthy, I’d go with the 1/2 inch per acre rule.
If you’re using a pond fountain for aeration, then a pond fountain with a 1/2 inch outlet diameter will be enough to aerate your pond.
That’s right…
When you’re using a pond fountain for aeration, then the 1/2 inch per acre of pond surface area rule is actually more than enough aeration.
That’s because pond fountains are actually more effective at oxygenating the water than diffusers.
The only reason you’d choose a diffuser instead of a pond fountain to aerate your pond, is if you need to aerate a deep pond.
In other words, if your pond is more than 6 feet deep, then you’ll want to use a diffuser.
This is because diffusers aerate ponds from the bottom up, while pond fountains aerate ponds from the top down.
Pond fountains work by spraying water up into the air, which then falls back down into the pond.
As the water droplets fall back down into the pond, they break up and become reoxygenated.
Now, because diffusers work by releasing air bubbles into the pond, and then letting those air bubbles rise to the surface, they’re only going to be effective up to the depth at which the air bubbles reach the surface.
That’s why, if your pond is deeper than 6 feet, then you’ll want to use a diffuser to aerate it, because a pond fountain with a 1/2 inch outlet diameter won’t be able to get enough oxygen down to the bottom of your pond.
