Pond Boss Forums AERATION Should I aerate? Super Cooling?

Can anyone tell me how cold it needs to be or how long for a certain amount of time before this "Super Cooling" will take effect in one's pond? I would like to leave my air running during the winter at it's current depth of 8 feet even for just a couple of hours a day so I would not have to start from scratch again in the spring with my air. I would prefer not to move it if I don't have to. I am going to say we average right around 41 degrees in the winter. Is Super Cooling even an issue for me at those temps?

Good question I'm in the same boat.. I was thinking of making a separate diffuser station that could handle my full airflow that would be a short run too shallow water from my compressor that was removable each winter..

I am starting to think about this with the pond being right around 8' right now and my shallow water diffuser out of the water. If we don't get rain this fall I am not sure what to do. Afraid there are too many fish in the pond to not aerate but not enough depth in the pond to aerate safely. Maybe I need to get Nate to bring over some folks and fish out some of me bluegills. Just haven't had the time to do it myself.

Hey lassig,

Your shallow fuser really needs to be in about 3 to 4 foot of water where your from. It can get darn cold up there in IL! For long periods of time. I would think you will have to move one or the other to 3 to 4 foot I bet. Here in Arkansas we just don't get that cold for very long if at all. If we get below freezing it may only be for a few days. With that said I am wondering if I can still run my fuser at the 8 foot mark mainly so I don't have to start all over with the baby step process of turning on my air in the spring as I don't live at my pond and it's hard to do the whole process that really takes about a week or so if you do it right. I just don't know when "Super Cooling" will really become an issue? Or if I should not risk it at all??

I would also love to hear what the experts have to say about "super cooling". My ponds here in MN average 4.5' with the deep spots 6.5'. For 8 years I have run two windmills on a 1 acre pond and for 3 years a solar powered on a 1/4 acre.

I have had one fish kill due to lack of aeration in the 1 acre pond but have never seen (or maybe don't know what to look for)the effects of "super cooling"

The windmills obviuosly run intermittently and the solar runs at 3-4hrs/day with an average of .75-1 cfm

I leave my stones in the same locations summer and winter

This is a very timley question for us MN people since winter is only a few weeks away

Good topic that needs more practical research. As usual "it all depends". My friend showed up and I will get back to this later. In the meantime let's have some input from others.....

I run my winter diffuser at 1/3 the deepest pond depth.

I have seen a pond with winter water temp at 37°F for a month or so, but not colder than that.

Scott,

I placed my shallow diffuser at 3 feet last year with the pond being 11 to 12 feet deep. There isn't much room left in the pond so even at 2/3' deep I am afraid it may turn the complete pond over.

Super cooling, as my old foggy mind recalls it, was something that was discussed early in the history of the Pond Boss Forum. I was a part of those discussions and probably contributed to creation of this aeration concept in ice covered water. The super cooling in winter has little impact in ponds that have little or no ice cover. As more discussion and knowledge on the topic has been gathered, I currently think this super cooling concept may be over rated for most warm water fish, and all cool water fish and cold water fish. The exceptions are with the southern adapted fish varieties or species such as Florida LMB, CNBG, RES, etc. and maybe some CC or blue cats.

Similar to what 'esshup' noted above, the coldest temperature that I have measured the water temperature of aerated ice covered ponds is at 36F in a pond with full depth bottom diffused aeration, 24/7 aeration, and cold winter temps for weeks with air temps below 32F and some close to 0 or below.

Cecil Baird1 and a few others have noticed redened mouth teeth areas of LMB in super cooled water. PB members concluded this characteristic was probably a stress factor and due to water temps below 39F. Others have noted increased deaths of southern sourced RES during aeration in winter. This too was probable due to cooling of aerated water in winter below the 39F temperature. Thus there is evidence that super cooling can stress fish. The degree of this super cooling stress will depend on several variables including fish species.

After discussions with Matt Rayl (Aquatic EcoSystems Ecologist) and my testing, we conclude the super cooling is probably over rated in northern waters inhabited by northern adapted species. This is because most of the northern species readily inhabit streams that develop water temperatures that are significantly lower than 39F in winter. I've measured frozen weather creek temperatures that have been as low as 34F with no observed major stressors or fish deaths. These stream dwelling northern fishes are adapted to moving water with quite low winter water temperatures. These fish survive year after year. Thus I think the super cooling concept does occur, but its impact on nortrhern adapted pond fish is minimal and less of a stressor compared to very low DO due to no pond aeration in very cold winter air temperatures. Would you rather have your fish stressed in 37F water temps with aeration or dead without aeration in 39F water in a severe very cold winter? However there is a lot of 'middle ground' with operation times and placement of diffusers for aeration during winter.

More testing an input on this topic will result in an evolution of the super cooling concept.

So if I just turn mine on long enough to open water above them I wouldn't have too worry about super cooling?? Also in really cold freezing temps running my diffusers would they even completely thaw through surface ice??

In that pond that I referenced above, the RES stayed alive....

BGK, yes, the aerator will open the ice. After I had a winterkill in my pond (I purchased the house and property in November but didn't move in until March and the pond winterkilled) I added a bottom diffuser aeration system the next winter. I didn't have a boat, nor a way to get the diffuser out to the deepest part of the pond. So, I waited until the ice was thick enough to walk on, and walked out with my chainsaw. I cut a hole large enough to get the diffuser thru the ice, dropped it to the bottom and turned it on. The next day there was a 20' dia. hole where the diffuser was. IIRC, the ice was about 3"-4" thick where the diffuser was placed.

The upwelling moving warmer water from the deeper parts of the pond will "eat" or erode a hole in the ice fairly rapidly as esshup indicated.

hey bill thanks for that input. i really wasn't sure what i could or could not do. so from what you said above here in arkansas i should not have any super cooling issue as we hardly ever have total freeze over of our ponds. i just want to keep it running if i can so i don't have to start all over again. i can turn it down but don't want to turn it off if i don't have to.

thanks,

Thanks for the info Bill. If you guys ever have a need for a frozen northern pond for any kind of temp study, I volunteer mine. Shucks its frozen over 6 months out of the year.

Another way to put your diffuser in. Tie a rope on it and walk around the end of the pond. Go to the spot you want it and pull the diffuser in.

John K's idea works great only for those that don't have the pond bottom littered with fish structure. For pulling in a diffuser it should be built to slide easily down the bank and across a mucky bottom.

This is a interesting topic. I too have wondered about super cooling in that I have a very small 1/10 acre backyard pond in NW Ohio that I have been discussing doing a put and take of trout this winter with the experts here. I use a variation of the RC 51 system.

I just last week suffered the very cool temps to swim out and move the 3, nine inch diffusers to the a depth of 4'. I plan to continue running the system 24/7.

I have personally caught 100's of pounds of steelhead and browns in northern rivers that run so swifty they never freeze despite temps being in the single digits for days at a stretch. This in mind I have doubts that super cooling is a concern for me. I have spoken to several folks and the messages are mixed.

I will keep you guys posted as go through the winter.

It's not a concern for coldwater species from my experience.

You swam to reloate your diffusers? I tie a polypropolene (sp?) rope (yellow in color easily available) to my diffusers and leave them on. When I need to move a diffuser I pull the ropes.

The only time this guy gets into cold water is when he falls through the ice!

Note to self. Install yellow rope in the spring. Brrrrrrr !

This is a very enlightening discussion for me. I'm wondering - do you guys install two (or more) diffusers to allow you to have one at the deepest part of the pond for warm weather and one at +/-4 ft. for cold weather? And if so, do you have a tee in your tubing with valves to direct the airflow?

A long time ago I read that the deep water diffuser should be elevated approx. 1/3 of the total depth above the bottom. Does this still conform to today's technology? If so, how do you elevate the diffuser off the pond floor? I was thinking about a 55 gal. drum full of concrete. But that's a whole bunch of bags of Sacrete!

Elsie,
I am far too new a pond owner and much too inexperienced with most of this to be able to provide much more than a report of my own conditions.

I could easily place two diffuser sets but the fall location is in the middle of the wading area we swim in during the summer and so I would not want the risk of entanglement. Moving is not that big a deal I just need to plan better for next year.

Currently I have triangle of 3, 9" neoprene diffusers supplied by a one and half inch line running back underground to my barn approximately 75' from the edge of the pond where it is attached to an Eco-7 pump. The water displacement in my little 1/10 acre pond is amazing and I attribute that displacement to how quickly my otherwise sterile body of water sprang to life and maintained it's health through the entire drought while others around me literally spoiled under the heat and dry conditions. Also the triangle is attached to a weighted plastic milk crate to elevate it 15" off the bottom. This was a modification I made within the first week of operation in that I quickly found that having it directly on the bottom caused the clay in my new pond to become constantly suspended. Once elevated the pond cleared almost overnight and never turned back.

I have been monitoring temps at three depths and so far have been pleased to find that they are holding very close to NOAA reports of nearby natural bodies of water like Lake Erie, Indian Lake and other large reservoirs. I figure if mother nature has it under control on those unmanaged bodies of water who am I to argue.

I just did my morning walk around the pond and checked temps. 60 degrees at 4', 57' at 6' and 55 near the bottom of the deep end in 11-12' of water.

Like Cecil had said given that I have only trout in the water for an over winter grow out and harvest I doubt that super cooling will be an issue for me. Here is hoping anyway.

We ue multiple diffusers, and switch from one to another. Yes, there's a manifold in the compressor cabinet that has valves on it so each diffuser line can be regulated, from full open to completely closed. That's needed because a line that is 200' long and in 10' of water will have less air than a line that is 75' long and in 5' of water, and both diffusers are running at the same time. The amount of air going to the shallower diffuser has to be regulated to get the same amount of boil from each diffuser when running both diffusers at the same time.

I've rigged up the winter diffuser in my pond so that it rises up off the bottom when air is going thru it so it's about 1/4 to 1/3 the total pond depth. When it's turned off, it's laying on the bottom.

The summer diffusers just have to be up off the bottom a bit, not a whole bunch. Just enough to keep from stirring up the bottom sediment, but close enough to the sediment so that the water at the very bottom isn't anoxic.

If I had a diffuser placed in a swimming area for the winter, I'd want to move it during the summer too.

Esshup.... Have you posted that setup somewhere in the past? It would be interesting to know how you accomplish this....Thanks,Jim

Nope!