I have been told by some knowledgeable people who aerate in my area to place my diffusers in shallow areas (3 to 4 feet in a 15 ft deep pond). Was also advised not to destratify the pond. Their reasoning is due to us only being at pond in remote area maybe once every two weeks, if the aerator loses power or breaks down there would be less chance of a fish kill. So the way I take it is totally destratifying pond is good for both pond and fish but serious problems could occur if pump breaks down? Just wondering what you guys think of this. Pond is in eastern iowa, one acre, in timber with a lot of leaves falling in. Max depth is 15ft.

If the pump breaks down and quits the pond just goes back to being a pond without aeration.

4' depth would be a recomendation for winter to keep a hole in the ice.

A slow start up procedure is needed in deep water in an old pond so not too much toxic water is mixed in all at once.

I'm in Kansas instead of Iowa so will let someone closer to your area chime in, but for summer aeration the idea is 1. keep water mixed so it does not stratify preventing the possibility of a "turn over" event and resultant fish kill and 2. keep water mixed so oxygen gets to deeper levels so fish have more usable water.

The only way I could see the aeration quitting being a problem is if the carrying capacity of the pond increased over time to take advantage of the additional aereated water and the resulting fish increased population were forced into the upper water as the thermocline established the fish would be crowded into a lesser amount of water.

But I am no expert. The experts may have a differing view.

Snrub, thanks for the information. Pond has no wind so is very low in dissolved oxygen.

Wind is only a possible part of D.O. in a pond.

If your pond is 15 feet deep then your diffusers need to be in at least 13 feet. IMO. The entire water column needs to be mixed like Snrub said only reason you would have a fuser in 3 foot of water is to keep a hole in your pond during ice and snow times. Remember warmer water holds like half the amount of D.O. then colder water. So you want to be able to mix the deeper cooler water which will then mix with the warmer water and cool the entire pond down. This is why a lot of folks only run their air at night when it's cooler, because during the day the sun will heat it up man. Plus the sun will also produce D.O. with your plants in the water during the day but at night the plants do not do this they take D.O. from the pond it's a slippery slop this time of year with the hot weather and ponds. Just about as slippery as when it's freezing cold out. Each time takes special management depending on your pond and what's in it and how many fish are in it and weeds and all. Bottom line though is if you can put air in your pond your doing the right thing. If it were me I would put it at 15 feet deep on some kind of crate to keep it up off the bottom a little say 8 to 12 inches. Then do as Snrub says and follow strict start up procedures I am sure you can find them in the air section of this forum it's been talked about like 1 million times!! lol

Good Luck,
RC

The only way that would be true is if you are pushing the carrying capacity of the pond and there wouldn't be enough of O2 in the pond for all of the fish. If you aren't pushing carrying capacity, then like others have said, it will revert back to a non-aerated pond.

Everyone, thank you for the replies. Very informative. It looks like I will be going with a Vertex Pondlyf aeration system. Vertex will be getting back to me with their recommendations. Our biggest hurdle is trenching 900ft of poly tube from aerator to the manifold by pond. This due to the fact that we will be trencing through heavy timber. We are not sure how deep to bury the line. I found some 5/8 inside diameter tubing that would cover that length with only two couplings. Has anyone had experience trenching through timber? Also, Vertex recommends using 1 inch tubing. I'm assuming thats outside diameter. We were planning on burying it about one foot deep to keep the animals from burrowing down and chewing on it. The entire 900ft is downhill.

I would order it from Hoosierpondpros.com!

Thanks for the recommendation!

We have run air line underground over 1,200 feet to a pond. We were pushing more air than you need, and we went with 1 1/4" poly tubing for the run. While you might be able to get away with the 5/8" tube, I'd feel better if you ran 1" i.d. tubing. Less restriction over that length run, and less chance for a dip in the tubing to collect water during the winter and freeze.

I have a client that is using 3/8" ID tubing to run 900' to his pond, but he is only pushing 1 CFM of air that distance and he is seeing about 3 PSI back pressure from the friction of the air going through the line. He also has problems during the winter of it freezing up and plugging. We installed a anti fre3eze system from Koenders to solve that problem. It injects Isopropyl Alcohol into the line to prevent it from freezing.

If I were doing that job there is no way I would be using a traditional trencher (of course I am imagining trenching thru my timber. No idea what yours is like)!! I would only do it with a trencher mounted on a skid steer. It will cost more money, but it will go much faster. Also, it would be easier to bury it a lot deeper with a skid steer trencher. I would imagine in Iowa you would want the line deeper than 12". Just IMO

Move diffusers (or keep extras) in 4' of water for winter aeration only, and the rest of the year, place diffusers in the deepest water. At a 4' depth, bottom disc diffusers will not be deep enough to do much to improve dissolved oxygen levels except under ice by keeping holes open.

If you have leaves entering, and do not break the thermocline, you are not adding oxygen at depth to support aerobic bacteria to speed detritus decay....and also oxygenating the 50% or so of your water volume below the thermocline in case of a failure.

It could take a couple weeks or so for the bottom water to become delpeted of O2 also, if there was a failure, and worst case scenario is, you have the same oxygenated volume as you do now, without aeration.

Couldn't agree more with the skidloader trencher. We will definately use this approach plus chainsaw. I will check out the hoosierpondpros.com site. Vertex just emailed that the tubing should be one inch inside diameter. Also makes sense to put diffusers deep to break thermocline and degrade dead leaves and such in bottom of pond.

One other question. When pond was dug in 2012 the plan was to be 18ft deep at the dike end. That summer we had a very bad drought in this area of Iowa. Contractor got to 16ft deep and hit water (spring??) If the pond is spring fed from the bottom it should not drop and always be running out the spillway pipe at the top of the dike shouldn't it??? It drops a foot or two sometimes. Contractor says it's the best water holding pond he has ever built. Stated he would be a millionaire if he could get all his ponds to hold like ours does. I do notice all the other ponds in the area do drop a lot more than ours does. (understand I was not complaining, he is my neighbor and I'm very happy with the construction) Just don't get the whole spring fed thing.

Thanks for all the great info, love this forum.

That is great that your pond is holding that level. Typically when hitting a spring (groundwater) the water pressure in the pond will exceed the water pressure in the ground during times of low rainfall and the pond will drain faster. There is no one way valve on springs....... It sounds like your pond is at a lower elevation than some of the surrounding land that has water in it.

I found some 1in piping for air from compressor to manifold by pond. It is PEX oxygen barrier in 500ft rolls. We will be using two rolls with one coupling for the 900ft distance. (leaving a small makeshift manhole at coupling site). Does anyone know if it is ok to bury red PEX oxygen barrier piping? Found some on sale cheaper and closer than regular poly tubing.

I don't see why not, it's buried in concrete all the time in floors.