Pond Boss Forums AERATION Should I aerate? aeration in winter

Bill D one other thing to remember, the aeration does not turn the pond into one big homogeneous mass. At least not in my pond. Maybe if a person had excessive water movement it would.

In my pond on a hot summer day, I can swim towards an air station and about ten foot away feel a distinctively flow of cool water at the surface. The top is heating faster than the water flow from the bottom is mixing.

Who knows, maybe I don't have sufficient flow for my size pond. But I would think at the desired one turn over of water volume per day (or more) water temperatures within the pond are still going to vary.

On the other hand, in my 1/20th acre forage pond and 1/10th acre sediment pond, I may have enough air flow to keep them homogenized. But not in my 3 ace pond.

So mixing at night or mixing in the day only may not get the results imagined, unless a person has a fairly high flow rate of water to turn the pond over fairly quickly. Takes time to heat or cool or mix millions of gallons of water.

Just the way I see it. Don't know if it is right.

100% agree. I am not saying there is a huge difference, just saying there has to be one...unless the second law of thermodynamics is wrong.

I have wondered about that. Is it lack of DO that kills the trout or the temperature or both? If you could somehow raise the DO level in 80 degree water, would they survive?

It's a problem of both. Trout need a minimum of 5.0 ppm O2. Take a look at a DO chart and see where that falls.

A client that has both surface agitation and bottom diffusers has had Golden Rainbows living in 78 - 79 degree water, but they did not make it through the summer. O2 was at saturation levels when I checked it.

Several months ago I remember reading a post by one of the aeration experts where they gave an approximate time for a winter diffuser to cut thru X inches of ice. Anybody remember the numbers? Just curious, I know I have a thick ice cover here. Got some snow on it and fired up the winter diffuser at 7:30 this morning. Still no sign of breaking thru 5+ hours later. A lot of air (4 to 5 cfm) coming thru that diffuser. I walked down and checked, thinking I might have a frozen line but system pressure is normal and all appears operating as usual.

Has to be one big bubble under there!

Bill, to speed up the process I will go out and drill several 3/4" holes (largest long-bit I have/had) over the diffuser area. It breaks through much quicker! Of course an ice-fishing auger would be preferred, I just don't have one.

But a forewarning: I had my system running which had built up pressure, likely what you have now in your pond, and when the drill broke through the ice,,, well,,,, old faithful went a spewing upwards!

Kinda cool actually, but don't say you weren't forewarned

Oh, and be sure your bit is tight in the drill! Mine apparently wasn't and it slipped right down the hole to the bottom of the pond. So now I'm using my last long-bit which is 5/8"

I can see how that would help but there ain't no way I am going out on the ice now! Still no hole after 7+ hours. I am wondering, as the ice cover has been on there for quite a while, if the water table dropped some and there is a gap between the bottom of the ice and the water level. Anybody ever seen that?

Never mind.....There she blows! Mission accomplished 7 hours 32 minutes to break thru and it is off to one side of the diffuser so must have found a thinner spot.

Bill, I've always understood there to be an air gap between the ice and the water, but maybe I've been watching too much TV

In the past, with all the air being pushed against the ice, I've seen it escape at the shoreline but also wondered how much pressure it's creating, if it is, such as yours running for 7 hours before breaking through! I do know there has to be a tremendous amount after witnessing Old Faithful on my own pond.

Does all that pressure have any adverse effect on the fish (stress to a harmful degree)?

Keith,

I've always heard the same thing about the air gap. The movies where people fell thru the ice and get air in the gap. If there is a gap, how can ice keep getting thicker when it's not touching the water? The ice fishing guys should know if they see a gap when they cut their holes.

This is the first time I've seen my winter diffuser blow a hole that's not directly over the diffuser location. This one is starting just a few feet from shore, about 20 feet from the diffuser. Maybe its water depth? Although the diffuser is in the same spot as last year, the November rains brought the pond level up. The diffuser is in 7 or 8 feet of water this winter instead of 3 or 4 like last year. It's weird!

IMO I don't think you can build up pressure in the pond very "high." Your compressor has limits on the pressure it can output.

If the water level drops after ice forms there will be an air space directly under the ice. This is an indication that your pond likely has some sort of seepage - leak.

Yep, it's a water table pond.

I've had ice cover for two weeks with some on and off thin snow layer. Today there was 3.5" of ice and 2" of snow cover. At 13 ft deep water at one ft deep DO was 11.8ppm, 39.2F with 90% DO saturation whereas at 2" from the bottom DO was 11.4ppm, 39.6F with 85% saturation. I will not start aeration until the DO on the bottom is 2ppm.

Yea, about 150 psi. You really don't want to be standing around it when it blows.

Wow! The relief valve on my aerator compressor is set at 35. Why do you have yours set so high?

Typically in a pond where the water level drops, the ice along shore will slope down to the water, then the ice floats on top of the water. Ice will have a hard time staying horizontal if the water level drops as it is only frozen to dirt.

Just like you trying to hold a sledgehammer at arms length, the further away from the anchor point (your shoulder) the harder it is to hold up. Ice does the same thing.

Somewhere on youtube is a video of ice in a pond breaking from air forced in from an aerator. The ice looks like a balloon.

For me in my location, with only running during the day time hours, bitter cold freezes up the ice over the aerators every night. It takes a while to open a hole sometimes weeks if I don't go and drill holes over the diffuses (which I hate doing!)

This season we placed some logs floating over the diffusers. They draw the heat during the day, provide a lot of surface area and allow a hole to open quicker the next day. I will be replacing them with "man made" ABS logs this weekend. I think beavers in the north have the right idea for keeping water open

This has got to be the problem at my place. We must have just not had enough consecutive hours of wind to punch through.

I figured that air would move horizontally along the ice and escape at the shoreline or something. Are you guys saying that it will actually stay trapped under there and lift the ice?

Is there any benefit to the aeration if it cannot get a hole open in the ice?

wbuffetjr I think you may be right about not having enough hours of wind at any one time for your circulating pond water to cut a hole up thru the ice. mnfish may be on to something that you could incorporate next season. Even better for you with all your snow cover might be to drive some vertical pipe, posts, or the like, into the pond bottom near your diffuser. The vertical pipe would absorb heat from the sun and tend to have thinner ice right by it.
Your circulating pond water would have to do less work to break thru the ice when the wind did return. Just a thought.

When first starting my aerators in winter I always drill a few holes above the diffuser. Air that breaks the surface seems to cause more splashing action that seems to melt ice faster. NO proof just guessing and watching air-water splash up through the ice holes.

WBJR,

IMO another factor to consider is amount of air, CFM. If you are running low airflow, I would expect longer break thru times. I don't know your setup CFM capability or number of diffusers. IMO Since you can't run 24/7, I would push all the air you can generate thru a single diffuser to maximize your ability to create at least one hole in the shortest amount of time.

FWIW it took me 7.5 hours to blow a hole thru probably 4 or 5 inches of ice at 4+ CFM thru one diffuser station. I suspect I could probably open a hole with 1 CFM but it would take a really really long time running continuously. I would be surprised if I could break thru at all running 1 CFM only 8 hours a day or so.

I fired up 2 of my 4 diffusers (the shallow ones) late Friday afternoon to get some open water due to a few weeks of snow cover and they still haven't blown through as of this morning (nearly 3 full days).

What's happened though is that it's opened up 2 small areas near the shoreline of the deep area, about 100-150' from each diffuser, where the air is now escaping.

I normally do as Bill Cody suggests, drilling holes above the diffuser but I got impatient on Friday and it was getting dark, so I just started them up.

Now I have all these things running through my mind of what's being stirred up with no place to go other than being trapped below the ice until it escapes near the shoreline. And of course it's now not safe to get on the ice to drill holes.

I'm tempted to shut them down, let it refreeze and go back out to drill holes. I know Bill Cody says he has no proof of how drilling the holes help, but taking the least path of resistance, I can't see where it wouldn't and it's always worked for me.

Worked so well I decided not to do it, I guess

PS - the gauge on my compressor reads 5 cfm with both fully open. If I close one, it will be at over 10 unless I pull a hose to release pressure.

4Corners - I am definitely all ears and appreciate any suggestions. I think you are right. I need to come up with something this summer to put out there. I would just want to be able to put whatever it was in when I leave in September and pull it out when I come back in the summer. Just wouldn't necessarily want to look at something out there all the time.

Bill D - this is straight from Koenders...
"The compressor is capable of pumping 28 lbs pressure, but will only pump the amount necessary to push air into whatever depth water you have...for example 10 ft of water depth will require about 4 lbs. (aprx .4 lbs per ft of depth) And it will only require about a 9 mph wind to do it!
It will pump useable pressure as well as volume. The volume again varies with water depth. At 1 ft of depth you will get 3 cfm...at 10' about 2.5 etc."

I have 2 vertex diffusers out. One at 6' and one at 10'. Pond is 22' at deepest.

As far as wind speed up there..... My buddy spent the weekend up there at his place (350' lower elevation than me). Last night they had a big storm blow in and got 20" of snow. He keeps a windmeter out that he said recorded an average windspeed of 20mph! I KNOW we get a TON of wind up there when I am there. I expected this windmill to be more effective than it appears to be.

Having the object in the water is definitely an interesting idea. Check out this picture. The snow around the little generator shed and the big rock have clearly been melted. I can only guess that was from the sun heating them up. The sun up there is definitely "different". You could probably fry an egg on the hood of your truck when it is 70 degrees outside. Maybe the metal pipe trick would work.

Wow that"s some serious snow depth! Good thing your ponds and lakes up there are probably oligotrophic!