Pond Boss Forums AERATION Should I aerate? Windmill is pumping, but can't open holes in ice!

My pond is in WNY. The winter here has been pretty brutal. I have not been to my lot in probably 2 months, last time I was there the ponds had open water holes from the aeration. I went and checked yesterday, and the ponds are covered in what I would guess would be about 1ft thick ice and about 24 inches of snow on top of that. The windmill aeration has not been able to keep up with the low temps and snowfall in terms of opening up holes in the ice. Also, we had no January thaw this year.

Long story short, should I be concerned about drilling holes in the ice above the diffusers? I'm wondering how thick the ice is above the stones and whether or not that is a dangerous proposition. Is it required to have open water for the anaerobic gases to escape? If not, how long can the pond be covered in ice to where this will become an issue?

I don't think we're going to have a thaw anytime soon...

Every pond is different. I had a clients pond winterkill with a few inches of snow on it, cloudy/foggy days and no wind for 2 weeks with a windmill aerator. How old is the windmill system?

I have an Outdoor Water Solutions AWS0139 24' windmill that I custom added more sections to it to bring it up to 36' tall.

I installed this in August 2011.

Do you have a pressure gauge on the airline? If so, you can check to see if the windmill is actually pumping air into the pond when the wind is blowing. If not, that would be the first thing to check - is the windmill operating properly? I have to rebuild a Koenders for a client when I get back from the Pond Boss Conference - it stopped pumping air after 4 years. Unfortunately to do that I have to get to the top of the windmill............

I do not have a gage. Two winters ago I was not getting air, what had happened is condensation built up in the line, froze, and then the line popped off of the pump. 40 foot extension ladder, white knuckles, etc, I was able to fix it.

When I checked it yesterday, there is definitely air going to the lines which supply the diffusers.

I am very confident there is aeration, but we have had a lot of still/cold days, enough to allow the ice to get real think. My assumption is the bubbling action is just not going to be enough to open up holes.

I also hate to just walk out on the ice over the diffuser and fall through.

I had a few winters where I had no aeration at all and the ponds were iced over for months without fishkill, but I just have a feeling that this year could be different.

A small hole above the diffuser would allow the bad gasses to escape rather than be spread out under the ice. During really severe winters and/or clogged diffusers expect periodic winterkills with 'weak' amounts of aeration. Always monitor the ice thickness as you approach the diffuser location.

So I made the trek to my land this morning, bringing what I thought I needed to get my bulldozer and excavator running. Bulldozer to clear the ~24" of snow out of the 700ft long driveway, and my excavator to drive up to the edge of the pond to use the bucket to clear an open water area as near to the diffuser as I could get.

When I approached the ponds I was happy to see an open water spot above the diffuser in the large pond, no hole in the smaller pond. One windmill feeds two ponds and I have a flow control valve to meter the air to the small pond. I opened that up a bit and hopefully there will be some open water on that pond soon.

There must have been some more wind the last few days, I'm amazed the aeration was able to cut through that thick ice. It's nice to have an "easy fix" once in a while... I'm glad because tomorrow's high temp is -2 deg F.

That's good news!!!

I actually did this about a week ago. I had the aerator off for a month, then with 8 inches of ice I drilled a few holes on top of the diffuser and turned it on. Wow there was a rank smell coming up thru the holes.

One has to be cautious when you start bottom diffused aeration after oxygen depleted water develops on the bottom. This applies to winter and summer aeration. The thickness of the depleted oxygen layer on the bottom can vary depending on several things, but it depends mostly on the eutrophic nature of your pond and water clarity. More nutrient rich and more turbid the water usually means a faster depletion of DO that will occur. The faster it occurs the thicker the bad water layer becomes.

When you begin bottom aeration after depleated oxygen conditions occur on or near the pond bottom, it can cause decreased oxygen and toxic water problems throughout the pond as the currents spread out and mix the water. It all depends. Rank smelling water is a sign of toxic water that is caused primarily by hydrogen sulfide. Hydrogen sulfide is very soluable in water and in low concentrations it is toxic to fish. Normally, depleted oxygen in ponds begins near the bottom and proceeds upward toward the surface where dissolved oxygen (DO) is usually the highest. If you move a large amount or enough of the DO deficient and toxic gas water to the surface this can degrade the top water enough to kill your fish. Some species and sizes of fish are more tolerant to low DO than other fish. Low DO and toxic gases are a double threat or stressor to your fish. One may not have killed them, but together, all or some may not be able to tolerate both conditions.

The best thing to do for winter aeration is to set or suspend the diffuser in shallow water. When the diffuser operates it oxygenates the surface layer first. Then the currents gradually spread out away from the diffuser enlarging the aerated zone both shallow and gradually towards the depths. As the low DO develops on the bottom and becomes intolerable to fish they will instinctively move upward towards generally better water quality.

The local newspaper outdoors writer called me today about low oxygen problems in ponds at close to the end of our current harsh cold snowy winter. When the article appears Friday, I will provide a link to it.

The idiot that I am, been there and done that! 1 acre worth, 5 years of fish growth...Dead!

Here is the link to the newspaper article about my winter pond aeration interview plus other ice covered pond topics. In some areas of Lk Erie the ice is 2 ft thick.
http://www.bcsn.tv/news_article/show/484226

Darn, I didn't know about this. Now you are making me more nervous

This has been the worst winter yet since my pond has been stocked. To date I have just let the windmill aeration do its thing with the diffusers at the bottom.

As long as your windmill is working and pumping air to an open water area at the surface, your small pond should be okay oxygen wise. I am taking measurements and learning that cold water of winter mixes very easily compared to summer temperatures. I think your working windmill is mixing large volumes of water in your small pond and expanding oxygenated zone pretty far from the diffuser. Come back to this thread when the ice melts and let us know how the fish community survived. Is the windmill diffuser centrally located in the deep area?

Here is where my diffusers are located, both deepest part of each pond: diffusers

I have been meaning to add another diffuser to the large pond, jus have not gotten around to it.