Pond Boss Forums AERATION Should I aerate? Winter aeration

I live in central Illinois and have a 1.5 acre pond with 2 diffusers. I had heard somewhere that I should turn off the one in the deep end and leave the other going all winter. Is this correct? At what point do I do this?
I have searched the forum but can't seem to find anything pertaining to winter aeration.

Thanks
Tom

If the two diffusers are at equa-distance in the deepest water of the pond I would use neither one in their present position and depth. Either bring one up close to shore in only about three or four feet of water, or run anorher airline and diffuser into three or four feet of water to your compressor. I've also heard of suspending a diffuser a few feet below the surface.

Personally i actually not only run a separate airline and diffuser to shallow water, I change out my 4 cfm compressor to a smaller 0.8 cfm compressor.

What you are trying to prevent is super chilling your entire water column but stll leave some water open to allow light in for photosynthesis that produces oxygen. Deep snow and no photosynthesis not only does not produce oxygen, it can kill the plants and then they use up D.O. By their decomposition.

A fertile frozen over pond with no open water covered by several inches of snow or more has a finite amount of days until it's in trouble. Decomposing plants that are not only not producing oxygen but are using it up via decomposition only exasberate the problem.

Thanks Cecil,
That's pretty much what I figured but I am new to pond ownership. One of the diffusers is already in the shallow end (about 4') so i will leave that one going.
Another question...
If I close the valve down a little on the one left running, will it put too much load on the pump?

I would bleed off some extra air by disconnecting the hose for the one not in use. You'll have to do some adjusting with the valves as all the air will want to go to the open one.

Another option is to let all the air travel to the shallow diffuser which will make a larger open water hole in the ice. IMO larger open water is better than smaller in ice and snow cover.

Here is link to another discussion about potential winter kill under the ice and snow:
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=28519&Number=365263#Post365263

Bill, with your option I agree on having more open water, but could it not depend on the type of diffuser being used and how much pressure it could handle?

I know I've bled air as Cecil suggests when I've had only one vertex diffuser open as I was under the impression I could damage the membrane.

Just a thought

What are these membranes rated for cfm? I know they blow up like a basket ball when no water pressure on them.

Cheers Don.

If you do a Google search for the brand you have the mfg. should have the specs available.

For example, here is the diffuser I am using

A single will handle 1.4-4.2 cfm, double will be double that for this particular diffuser. You should be able to find the same type info for your particular unit.

Keep in mind, your pump output will vary with the depth of water. Some pumps a lot (linear air pumps), others not so much (rocking piston or vane) depending on design. Your pump should have a performance curve also to tell you the output at a given back pressure (depth).

Dono A Vertex single disc (Generation 3)is a min of .5 cfm and a max of 2.5, however at .5 they will need more flexing and at 2.5 you will stretch the membrane over time but they will operate in this range.Middle of the range is best for all rubber membranes.

The fish farm near me and numerous other aeration "specialists" sell lots of single 9" disk unit diffusers with a 1/4 hp rotary vane compressor. Many of the 9" disks have a normal operation cfm of 0-3cfm and max of 5 cfm. Right or wrong - the disks are probably getting somewhat over stretched with only one disk per compressor at 3-4cfm per disk. Over stretching a membrane no doubt shortens its life span.

DonoBBD, if you can find a spec curve for your pump, like the following example, and know the depth of the diffuser, then you will have a better idea of the cfm lost at depth. This is a graph of a linear diaphragm pump which looses volume very quickly at depth. Likely whatever you are using, not nearly as much.

Linear diaphragm pump

The legend across the bottom is depth of water in feet.

This may skew the subject matter a bit. Is a compressor and a single diffuser capable of moving enough water to keep an open area in a pond with 24-30 inches of ice? Wouldn't a circulator do a much better job under those conditions?

Dwight, I'll cut a hole in the pond tomorrow and let you know.

"Wouldn't a circulator do a much better job under those conditions?" Good question if one has thick ice. I think most circulators have bigger hp motors compared to the standard 1/4-1/3 hp air compressor. It would be interesting to see a comparison of the two methods.

I do know once the ice is thick enough it's tough to get the upwelling water to cut it. Don't ask me how I know.

I didn't have too many issues with the big pond installing a diffuser and keeping water open after the ice formed, as I think there is relatively more warmer water reserve in the depths. Also the hole started out big enough for the wind to aid in keeping it open.

Different story in the smaller trout pond that is more protected from the wind and freezes sooner and deeper.

Going to blow snow off the trout pond today at least in strips like below. The hard part will be to get the snow blower back there through 3 foot + snow drifts!

hello all Derek here been sitting here in north canton ohio looking and fearing is the hole in my pond to big or to small.120ftx80ft avg depth 10ft. im thinking if temp is -0 as it has been here repetedly abig hole would not be a good thing? or am i thinking wrong.

Derek, what do you consider big?

Here's pictures of my pond taken a short while ago.

So much snow that the floating dock is barely visible.


Here's a closer picture of the open hole from the diffuser. It's in approximately 10' of water, but the diffuser is about 3' beneath the surface. It's a single membrane diffuser. I am running about 3.5 psi of air to it, and bleeding off extra air from the compressor so I don't blow the membrane.


A picture with a wider view. I'd say the open water is about 30' to 40' diameter. The platform that the feeder is sitting on is 12' wide.


I drilled a hole in the ice right by the floating dock. There is about 10" of snow on top of the ice, about 3" of water/slush, and 13" of ice.

I blew most of the snow off my trout pond today with the snow blower. Was going to blow snow off in strips on the big pond but ran out of time. Found water under the deepest snow next to shore on the trout pond.

Who knows, maybe I'm just allowing the ice to get thicker!

Scott,

is your diffuser under a float or attached to the pier? Is it attached to the duck decoy you use the rest of the year?

Edit: Looks like it's not near the pier.

It's a single membrane diffuser that is attached to a weight in front of the feeder. When the diffuser is working, it floats up off the bottom to the length of the rope. When it's off, it sinks back down and doesn't interfere with summertime fishing.

If you go to Google Earth, look at the latest image. It has the pier in it.

Scott,

I've never heard of them being anchored off the bottom. Is that an original idea or am I just out of the loop?

Cecil, something I thought up. Single membrane will float to the surface with the Vertex bottom line tubing attached (tested it first) and I needed a winter diffuser. But, I didn't want to keep pulling it in and out every year. I also wanted open water in front of the feeder so I could feed all winter long. Mission accomplished. When air isn't running in it (i.e. summertime) it is laying on the bottom and not in the way of fishing. I used either 1/4" or 3/8" braided nylon rope to set the depth. If the pond is at full pool it's about 1/3 the total pond depth. If the water drops, then it's less, but there is less total depth in the pond at the same time. That was the easiest way that I could figure out how to regulate the depth of the diffuser in regards to total pond depth for the winter with minimal work on my part.

Very clever! I knew they floated as I had one float up once when the bricks came loose.

Wow Esshup,that some thinking out of the box there.Think ill try that next year.I have two dual 9"in my pond one in the deep end and the other in the other side that I pull in for winter by walking to the end of the dock and using a 20' painting pole with a paint roller for a hook to fish out the line and drag it close to shore. Cecil my hole is about 6 to 8 foot. Just got a little nervous when it was below zero for days,and it was down to two feet.Bleeding off way more than half the air that I have.Going in to the negative temp here again in the up comming days.maybe i should make the hole bigger. Thanks for the pics.darn I love this site, have learned so much from all you Wise folks.

Be very very careful walking toward that hole if you're going to make it bigger. Make sure you check with your spud!

Derek, just try to have your winter diffuser holes close enough to shore that if anything goes swimming that it/they can get to shallow enough water to get back out. I almost lost 2 Springer Spaniels that way. I now have the diffuser closer to shore.

I use my personal pond for testing. That way if a test fails I don't have customers that aren't happy with me.

Oh man Cecil, I recall someone on a tread here talk about weenies! I have no ideal what i would be,been here on property for 17 years and have never been on the ice not even 1 time.took more chances than most when i was younger but after many many many,not so good outcomes have become super weenie! Yes Esshup my diffuser is about 5 foot from the shore.Think i just have the air bleeding off to much have never ran it this low.

Ok I getting concerned about my pond right now. Been running the shallow water aerator (3' deep) all winter when the temp is below 35, which most of the winter has been. For most of the winter the hole keep open was about 40' by 40' all the way to the shoreline. Since last weeks snow storm and the cold since the hole has gotten smaller and smaller and now it is only 2' in diameter. Is it by chance I have cooled the water in the pond to the point where my fish are in danger? Hoping the coming warming trend helps things out.

Lassig,

I think many of us are in the same boat. We are just doing what we can and hoping for the best. I blew snow off my big pond in strips the other day. I'd like to blow it all off but it's such an undertaking I'd probably be out there all day. Just can't get myself to be out there all day, nor do I have the time.

My take is if you had that much water open and your decrease to 2 feet hasn't been that long, your D.O. shouldn't be an issue. And like Cody said here recently, it's preferable to have some superchilling vs. low D.O.

IMO our fish will tolerate super cooled water a lot better than water without DO. As the pond water gets cooler it may result in a smaller aerator opening due to the water is not as warm (39F) and the melting at the opening is not as 'intensive'. I would still run your aerator as previous. If you are not applying all the air of the compressor then divert some extra air to the diffuser and the opening will become larger. A weather warming is coming the end of this week and next week. Then the diffuser boil opening will increase in size. If you want to know the current temperature of the pond water take a small thermometer and place it in a container that has a handle. Tie a cord to it, fill it with cold water and toss in into the boil area. Let is sit submerged for several hours. Retrieve the container and read the thermometer. Report your findings here.

Agreed! You should be fine!

Thanks everyone. Bill let me see if I can find something around and take the water temp. If I can find something I will report back

Derek,

There's a fine line between being brazen and being stupid. Sounds like you're being smart to me!

OK container in the pond with thermometer. Will check it later this afternoon. Here is what the hole looks like right now. It is a little bigger than this morning

I'm beginning to wonder if winter diffusers should be constructed differently than summer diffusers?

The goal in the summer is to move as many GPM to the surface as possible. Fine bubbles accomplish that more effeciently than coarse bubbles.

In the winter, its the wurface disruption and consequent moving water (waves/ripples) that keep the ice open.

Should we be using a coarser bubble diffuser in the winter to make more of a surface distrubance, therefore keeping the open water hole larger?

I have a cheap membrane diffuser in the winter diffuser location. I pump a LOT of air into it, and the diffuesr boil looks like it's 3" or so tall. There is a lot of water movement in the hole, and I've not seen a small open area in my pond this year. Other ponds that I've seen wtih little airflow and fine bubbles, have completely iced over in the coldest weather.

Cecil thanks for the encouragement,my mom always told every body I was accedent prown, wife just thinks Im crazy! But anyway like bill suggested think I wll go back to the pond and takes some temps.have a digital temp gauge with 8' cord,of course ill do it with a long pole from the shore.

One can always drill a hole in the ice and take the water temp about 5-8ft deep where winter water temps with and without aeration are pretty uniform at 4ft to the bottom unless someone proves me wrong.

The Pondmaster pump I bought comes with what they call a diffuser. It has a big hose barb to connect large 3/4" tubing from the pump and the other end is a plastic piece with a bunch of hose barbs that regular small aquarium hose can be attached to. The manual says this device can be used inside to run multiple small hoses to different aquarium tanks, or weighted and put directly in a pond to act as a diffuser. I would think it might work for clearing ice as the holes coming out of the 16 barbs are may be 1/16" diameter (not where I can measure it handily). Another way might be to use a piece of PVC pipe and drill 12-16 1/16" holes in it. A person could check the back pressure and keep drilling holes till it suited him.

I could not find a picture of the one that came with my AP100. It had twin rows of barbs 16 total. This one has 12 in a single row but will give the idea.
cheap style diffuser Note: not promoting this place or this product. Just using the picture as an example.

Just a thought from someone who does not use a diffuser for ice (yet).

I don't know Scott but I like your idea of suspending a diffuser. I may try that next year.

Bill Went out back to the pond,fixed me up a weigted temp gauge and turned the air off the diffuser,and for about and hour with it on the bottom at 3-4 feet it only got to about (34.8F).THink ill have to go out on the dock,into deep water and drill some holes and check from the bottom up.I was measuring only 5 foot from shore. don't no if this was good or bad temp.

PS! I did pull up the first green plant life ive seen all winter

Derek's aeration "my diffuser is about 5 foot from the shore. Think i just have the air bleeding off to much have never ran it this low." You may not find a lot warmer water than 34.8. A second measurement in a little deeper water will provide better information. I suspect that the mixing is spreading out quite a distance from the diffuser. I'm learning that cold water seems to mix differently than when the water is 50F-60F+. More measurements by you and others will be informative.

Just retrieved the thermometer. Reads roughly 35 degrees.

Good sign!

It took me 25 minutes to make a hole in 15 inches of ice due to dull blades on my auger. So suffice to say I only was in the mood to make one hole.

Highest temp I could find about 100 feet from the diffuser was 34.5 F. in 9 feet of water the deepest spot in the pond. D.O. was between 12 and 13 ppm from 0 to 5 feet and between 11 and 12 ppm between 5 and 8 feet.

I blew more snow off the pond today but I think my life saver is my diffuser that is keeping water open. In fact judging by the low temps (below 39 F.) I'm thinking water is circulating from the diffuser throughout the pond evidenced by the low temps.

Do you concur Bill? Bill I actually dialed down the air about a week ago.

I'd like higher temps in the deep water but if it's a trade off I'll take the higher D.O. levels.

I hope this helps our understanding of what goes on in a hard winter with deep snow, thick ice, and the use of a diffuser.

Just got a report from an ice fisherman that in the large pond he fishes, the fish are just below the ice and concentrated near an inflow. Sounds like a winter kill is imminent there

Cecil, I'll go out on my pond tomorrow and see if I can get a temp measurement in the deepest hole. I'll post time from start to finish on the augering part too....

I used my ice spud to chip a hole through 12" of ice. After 4"-5" I hit a water layer and had to chip out the remaining hole in watery slush. It took 2.5 minutes.

From the temperature data so far, it appears diffusers, even in shallow near shore water, will mix and circulate super cooled water for long distances and into deep water of the pond basin.

I think CB1 is correct. Fish near the ice cover mid to late winter is a sign the DO is absent in the deep water. DO is lost first at the bottom and is then consumed toward the surface, thus forcing fish higher and higher toward the top to find acceptable oxygen concentrations. Without light getting through the ice the water directly below the ice soon also looses it's DO and winterkill occurs.

I'm going to dig out the vexilar and see if I can mark fish. On second thought no I'm not. I'd have to spent another 25 minutes boring a hole!

OTOH I suppose I could reopen the hole I made today with my spud!

If you're going to go to the trouble of digging out the vex, you might as well dig out a rod and a couple jigs also.......

I don't want to stress them. They are worth a lot of money in sales and to lose one or have one deep hooked before they are harvest size is like flushing money down the toilet.

I will be fishing hard just before the female yellow perch drop their eggs, which is when they weigh the most and I can charge the most. And of course the male gills will come out at the same time. I have plenty of volunteers lined up.

Minimum size 14 inches on the perch and has to be over a pound on the bluegills.