Hi, I looked through the aeration archives and didn't see this question, so here goes: I have a 1-acre pond in southern Vermont, about 12 feet deep, which stocked itself naturally with brook trout through the inlet pipe - I may add some more in the spring. I want to add an aerator system to increase the water oxygenation and help the fish, and am thinking about putting in a solar system to keep my electricity costs down. Here's my question: if I get one without a battery, it is WAY cheaper - the battery-equipped systems are a bit out of my price range. If I am just aerating during daylight hours with a solar system, will the benefits extend through the night-time hours? No doubt it would be better to have it running all the time - just wondering if anyone has had experience with a daytime-only system, and if it is worth doing. Thanks!

Welcome to the forum!! I'm not an expert by any means...but have read a lot. Is there no way to get 110 volts anywhere near the pond? I know many have run black pipe or pvc a long ways to a pond so they don't have to run electricity.

I do not know about your climate, but you are trying to mix the water column when aerating. So your cooler water on the bottom, that doesn't have much if any dissolved o2 in it, gets pushed to the top, mixing with the warmer water that has dissolved o2. This will allow the whole water column to sustain life because all the water will have oxygen. That being said, when you run just during the day, your water will mix and eventually be close to the same temp all the way down. Here in the south that can be a bad thing when surface temps can get pretty hot. I would think with trout you would have to be careful of temps. Most of what I have read if you have to pick, says to do it at night after the sun sets then shut off when the sun rises. This actually cools the whole body of water, and adds o2. That doesn't help your problem I know.

Again welcome to the forum! Great place to be!

Peach is right down here it gets hot hot. Remember warm/hot water holds half as much D.O. then cool / cold water. I run mine at night only and some folks run 24/7 but I don't know anyone who runs there air system just during the day... but night time is a must as that's when all your plants and weeds are taking D.O. away from your pond not giving it. During the day the plants and weeds give you D.O. If it were me I would wait and save up till I could get a system with a battery. IMO it would be worth the wait.

Lets see what others have to say....

RC

FWIW, this pond doesn't get hot - it is continually fed by a stream (or a well when it's too dry to use the stream) - and it is in Vermont . I understand that brook trout are quite heat-sensitive, but they seem happy in there. They seem to stick to the bottom where it is cool - so I want to make sure they are getting the oxygen they need. Weeds are not currently a problem - pond is clear.

--Now I am wondering if it might make as much sense to run the aerator on a timer at night, hooked up to 110v (it's a short run, just don't love new persistent power usage if I can avoid). If it was just at night, wouldn't use so much power.

Take a temperature reading of the pond water during the day. Use a swimming pool thermometer and measure the top 12" of water and let us know what the temperature is.


Now for the other guys that say aerate only at night because the water temperature won't get as hot. Give me some concrete numbers please. What is the surface water temp during the day vs. at night in a pond that isn't aerated? How much does the temp change from day to night?

I hope it is ok as I am aerating in the daytime only! For Brook Trout as well!

Your main goal for night air is there is no D.O. being produced in the pond if anything it's being sucked out and that could be bad if you have to many fish. As far as big change in water temps... well obviously it's not changing that fast or that much or you would have other issues, but in general it's cooler at night hence the mixing of the water at night I would think would not be as detrimental as doing it when the sun is beating down on my pond at 103 degrees v.s. 74 at night in the dark. All you have to do is walk from the sun into the shade and you can feel a BIG difference. Is that the deciding factor to run air at night? No.. it's the NO D.O. being produced which is the deciding factor.

If my pond produced D.O. during the night and not during the day... I would run my air during the day surface water temps and depth temps IMO would be a secondary worry not a primary.

RC

If you can run 110 to your pond I would. That's what I did and put mine on a timer. I run my air from 8 PM till daylight and it shuts off. By doing this in my area I use about 10 to 11 bucks a month.

Thanks to everyone for your responses! I have a number of new variables to consider. I am going to get a thermometer and do some actual measuring, both at the top and at the bottom, to get a better handle on what I am actually dealing with temperature-wise. Let me also redefine my original question: If I only aerate part of the time (whether with solar by day or AC by night), is there still a benefit to the fish? Will the water stay oxygenated over the time that I am not aerating, such that it is still worth doing? I am trying to figure out if it is worth doing at all if I don't leave it on continuously.

It always seemed like to me that strictly from a DO standpoint bring up water from the lower region of the pond that has little DO would be best doing it in daylight hours. Mixing bottom low DO water with upper water that is loosing DO after the sun goes down seemed counter productive from a strictly DO standpoint. Moving that low DO water up from the bottom while there is still sunlight lets it oxygenate (via algae respiration) while mixing already oxygenated high DO water down to the lower regions providing a larger DO storage for when night comes.

So for DO it always seemed to me that if a person had to choose between day or night aeration that mixing water in daylight hours would be better than mixing low DO water at night when the low DO water had no chance to recharge.

But that is just the way it works in my mind. How it works in real life may be different and I am certainly no expert to say.

Then the issue of super heating the entire water body comes into play in the south. So it may be a case of "it depends". Not always do the changes we make to alter the environment to benefit one element of production prove out to be beneficial to all the elements. Improving the DO situation but stressing the fish with hot water might not be a net benefit.

Edit: I just thought about the air/water surface interface where O2 is also transferred to the water. So moving lower water up at night would benefit from that way of oxygen getting into the water. I was thinking of the algae producing O2 which would not be happening at night. So in short, I probably do not know what I am talking about. Disregard everything said up to and including this point.

Snrub.....As one who is trying to figure out this whole aeration concept (we have never done it at our BOWs) I gotta say I love your edit above! Too funny...BM61.

IF I had to make a choice between aerating at 12 hr night vs. 12 hr during the day, I'd pick the night.

BUT, with the caveat that the aeration system should be sized 2x the size of the system that would be running 24 hrs a day.

Ok, but you can't make a statement like that without giving your reasoning! Your logic. Or perhaps your experience?

Night because of no sunlight like you mentioned. 2x size system because of the number of turns required in 24 hr.