Pond Boss Forums AERATION Should I aerate? What depth to place diffuser?

Pond depth max. 15' 1 1/2 ac pond. No water or weed issues (yet). What depth should I place the diffuser for the summer, and should it be at a different depth for the winter? I didn't run it last winter, and all the fish made it just fine, but I expect to carry over a bigger biomass this Fall, and there aren't any submerged weeds in the pond yet. Unfortunately, with the economy hitting home hard, the budget this year might not have any room left for upgrading the aeration system. I need to spend $$ on 1/2 ac of groundcover seeds/plants to keep any erosion a bay - the ground is barren now. I have a single membrane diffuser 8" dia or so and a thomas pump.

Hey there~ I recomend placing the diffuser in the deepest part of the pond to maximize the lifting rate in the summer. If you choose to run it in the winter, place it in shallower water to avoid over cooling your pond's deeper water.

Thanks Sue. When you say shallower, how much depth should I leave under the diffuser for the winter? The deep hole is 16' now, but there are areas away from that that are a constant 10' deep without getting near the edge of the pond.

My neighbor is ordering an economy pond aerator kit from Ted shortly, and I'm tired of fighting with the floating air hose so I'm piggybacking an order for 100' of the premium sinking hose.

Hello esshup,

I thought I might take the opportunity to answer your winter operation depth question. Typically, 1/2 the depth of your summer operation is sufficient. So, in your pond with the 16' depth, winter diffuser depth should be 8'.

The whole idea is to create water movement at the surface and not necessarly aerate the entire pond during winter. A float tied to the diffuser should allow you to float the diffuser at that depth or, you can move the diffuser towards the shore to achieve that depth.

Happy ponding

Cary - Can you explain how you arrived at the depth of 8 feet for winter operation? Won't cooled, denser, sub 39F water currents approach the shoreline and then follow the bottom contour into water deeper than the 8ft diffuser level thus causing sub 39F cooling of deeper depths? Wouldn't placing the diffuser in shallower water than 8ft be a better option? Why not 4ft or 5 ft deep espcially if a sizable shallow zone is available for producing open ice free water and sunlight exposure?

Also how does one float or suspend a diffuser so it is stable and not wandering or moving around or tangling the float line during operation?

Hi Bill,

You caught me being too generalized again. Yes, the currents could approach the shoreline and possibly follow the bottom contour, but in my years since 91 working with these sysetms, that has yet happened.

Your 4-5 foot level would absolutely ensure this possibilty may not happen.

As for the float idea, one should use a 5-gal jug, to float the diffuser. To stop it from moving around, on the lower end, tie a cinder block to the diffuser. We did that in a deep water quary and it worked great. The cinder block was 112' deep and we suspended the diffuser at 30'.

Thank you for keeping me on track.

It sounds like the the floatation idea could work. Doe the type or shape of the diffuser make any difference in how well it suspends?
The size, maximum depth, and bottom contour of the pond basin probably have a lot to do with how the currents produced by the aerator will behave move throughout the pond basin. Smaller the pond the more likely currents will move deeper into the basin. Clear ice and convection currents from light penetration warming the water beneath the ice can also play role in contributing to water movements under the ice.

The earth will keep the deep water warmer in the winter than the surface. The air temperature will be a lot colder than the earth temperature. It's kind of like a cave. No matter how deep you go, the temperature is fairly constant around 55 deg. Typically, once you get below 4 feet even in the coldest winters the ground is not frozen. Thats why fish move to the deeper water in the winter.