Am I correct in understanding that I can run my bottom diffuser 24/7 year round? As winter is coming closer I want to be sure that I'm okay to continue running the diffuser. From what I can gather, I should move it to a little bit more shallow of an area if I wish to continue running it.

I'm just checking to make sure I don't do anything wrong as this will be my first winter running it

Correct. I'd move it to an area that is 1/3 to 1/4 the total pond depth, and to an area where the open water will be within a couple feet of shore. That will allow anything that goes into the water when the pond is frozen to escape out of the water without having to climb up onto the ice from deep water.

What about gasses getting trapped or stirring up all the water temperatures so there is no "warm" water under the ice?

Wondering about running my air all year 24/7 as well. I have four diffusers installed in my pond. Two in the two deepest ends and two on my shallow ridge.

Why would one only aerate the shallows and not the deep for the winter? 90% of our winter days for three months will be -6c and two weeks -10 to -15c.

Will the water passing the cool air of the surface really drop the water temp below safe temp for the fish?

I would have thought keeping the pond open and moving is the best one could do for the fish year round.

Cheers Don.

Water is densest at 39°F and sinks. Temps above and below that are llighter and "float". Having the diffuser up off the bottom allows the warmer water to collect at the bottom and not get mixed with the upper, cooler water. While winter aeration keeps ice off the pond, allows gasses to escape, and allows sunlight into the water for oxygen generation via phytoplankton, you have to get the diffusers into shallow water to avoid homogenizing the whole water column like you want to do for summertime aeration. The fish in the pond need a relatively "warm water" refuge to escape to for the winter.

I see so there could be a fish kill over the winter if left on in the deep?

I have two in the shallows and two in the deep all on their own valves. I am around 48-50F right now for top water temp.

If I had one that was in the deep next to my floating dock left on, as well to keep the dock free of ice, lower my ponds fish carrying capacity?

We are talking 40% of the pond left with no aeration for winter.

Cheers Don.

Winter aeration is totally different than summer aeration ~ it is really just about keeping some ice open to allow sunlight in and gas exchange, so it is OK if you shut off most of your diffusers. If you just run the diffuser under your dock you should be just fine. Cold water holds more oxygen and fish metabolisms are extremely slow.

Kind of glad I started this. For me, I got a difuser because it was "good for the pond" and I had the means to buy one.

Now I know not to keep it in the deep part during the winter, but here's another question. Why do I put it in the deep part during the summer?

Again, I'm doing it because that's where I was told to put it. And that's fine for me, but this is rather interesting.

In the summertime your pond will stratify and the cold water at the bottom will become hypoxic unless you turn on the diffuser.

Here is a GREAT old thread on winter aeration: http://forums.pondboss.com/ubbthreads.ph...ite_id=1#import

In the summer you want to circulate the whole volume of water in your pond to keep dissolved oxygen levels high from top to bottom. Warmer water holds less oxygen, metabolisms are increased with higher temperatures, which increases oxygen demand, and as Bocomo said, ponds stratify making the lower half of a pond or lake inhabitable. There is a lot more going on in the summer. Summer its about the total volume of water and a properly sized aeration system is very important. Winter you just need a little ice open.

Sue my dear when is a good time to switch the aeration over to winter? After I take the fish off feed around 45 to 50F? I am there now and the fish seem to have kind of vanished. No minnows sitting in the shallows now they all seem to be deep.

Cheers Don.

I have the same question. Water temp about 57 now. I'm pretty sure there is some information about when to shut off and when to start aeration in the spring somewhere in the archives as I have ran across it before. But can't seem to find it now.

I am also debating on putting a shallow diffuser under the floating portion of my dock. Most winters our pond will likely not freeze completely over. But we do have years where we hard freeze and get snow cover on ponds. Just wondering if it is worth the effort to drop a diffuser on ropes and small platform below the dock (maybe at 4' level???) and have it ready if needed. My other question is if a membrane double diffuser like this one will sit unused for months can start up and do its job without being clogged up or otherwise unusable? Not a good time with 40 degree water temperature to be getting under a dock to see what is wrong.

snrub