I've tried looking through old threads to find the answer to my question, but is there any reason not to aerate throughout the winter? We don't get much ice down here so it's not like there would be snow/ice over the pond for months at a time. I was planning to continue to run my aerator 24/7 throughout the winter unless anyone can suggest why it'd be a bad idea

I'm no expert on aeration but it seems logical that if temps are lower than 39F it wouldn't be good to bring the densest 39F water up to cool it more if diffusers are in deep water. If at, say half of max depth, I can't see that it would hurt anything. I do believe there are strain of cold water bacteria that benefit from higher O2 levels.

Yes move diffusers shallow to avoid super cooling water, although Lusk says aeration unnecessary for water temps below 60.

i aerate during the winter to keep the pond open.

I won't be running my air this winter. I did last winter, one diffuser at about 3 foot down with lower than normal air flow and only during the warmer daytime hours. I measured temps in the mid to low 30's from top to bottom out away from the diffuser area during the coldest of the winter. Running the air may of had some invisible benefits...it did keep a small hole in the ice open during the rare ice overs, but the downsides were...I witnessed no thermocline of warmer deeper waters, it seemed to keep the turbidity on the muddy side due to the crawdads stirring up the bottom and the diffuser keeping it kicked up, and it raised my electric bill I'm sure.

I will leave it off this year and measure the water temps to check the differences from last year and hope that the water settles to a clearer look.

I know I'm not giving you a definite answer, but these are the reasons I won't be running winter air. I think 24/7 winter aeration is not necessary, but depending on your winter time temps, it might not be a bad thing.

Right now I have 2 diffusers, the one in deep end hardly puts out any bubbles compared to the one in the shallower end. The deep one is in 8 ft of water and the shallow one is in about 4 ft. I guess I can just monitor my water temps to see if it's cooling too much. I'm sure the aeration isn't necessary in winter, but I was wanting to continue to run it to help with the bottom muck as long as it won't harm my fish.

If I lived in TN where ice/snow cover is minimal and the pond does not receive large amounts of tree leaves nor have lots of dead submerged vegetation, I would not run the aerator during winter. Winter operation consumes electricity, and more importantly it puts additional ware and tare on the compressor requiring more frequent rebuilds and reducing the total life of the compressor mainily motor bearings.

Ponds begin to turnover and mix top to bottom in fall when surface water reaches around 55F and more complete and 'easier' top to bottom mixing occurs when water is 50F to 40F. IMO when surface water is consistently 50F the aeration is usually not needed until the water again reaches 50-55F in spring. Most exceptions occur in areas where ice and snow cover persists for more than 2 months. Ice off in winter allows the pond to degas and reaccumulate DO top to bottom.

For me the "jury is still out" on how well a shallow operating winter diffuser creates a warm water refuge for the fish. Too little testing has been done on this topic to provide good, accurate advice.

Ferg - If your deep(8ft) diffuser hardly puts out bubbles compared to shallow then you should know why.
1. What type of compressor do you have? Brand, make, and model?
2. Is your deep diffuser surface clean or cleaned annually?
3. Do you have two ball valves at the compressor to control air flow?
4. Do you have a low 30psi air gauge that works on the compressor?

It's just a cheap Eco 7 aerator I picked up. I think the reason why the deep diffuser doesn't put out much air is because I have them both running off the same air line with a 3-way splitter and the deeper diffuser provides more pressure resistance. I think my setup works alright because the shallow diffuser is actually in the middle of the pond. Originally, I just had one in the deep end and it put out a lot of bubbles. I do have a lot of aquatic weeds and my pond is in the middle of the woods so it does receive a fair amount of leaves .

At most I would only run 1 shallow diffuser over winter.

Your Eco7 compressor is not designed to operate at 8ft deep so it desperately struggles to produce air bubbles at that depth. Ted Lea proved and showed this on the forum back when the Eco7 compressor was frequently discussed about 8 years ago. This is why the bubbles are noticeably fewer at 8ft compared to more air being pushed to 4 ft; the path of less resistance. Also as the diaphragm ages and becomes worn/weakens it will produce less and less psi.

Hi, I'm a new guy and have a question about aeration in the winter. I've read that by always aerating you will eliminate pond turn over and thusly the killing of fish due to low dissolved O2 water. After reading the comments above I noticed that this was not mentioned. Thoughts?
Size = 2/3 acre
Depth max = 16ft
One year old pond.


Btw, I live near St. Louis.

Roger1 - If I lived in StLouis with a one year old pond, I would turn off the aerator around Thanksgiving (or water temp 50F). Then begin aeration in spring when water reaches 50F. Winters should not be "hard" in StLouis area with snow cover minimal and for short periods for less than 2-3 weeks covering the ice. Your deep water of 16ft will have lots of DO to keep from having a winter fish kill in the 'newish' pond.

Shallow winter aeration methods are for more northern ponds that get long term snow covering the ice for more than 3-4 weeks. Your StLouis pond should probably have winter ice periodically melting. Any snow ice melting and open water during winter allows the reoxygenation of the pond.