Pond Boss Forums AERATION Systems questions Windmill vs Electric pump vs Paddle wheel

Windmill: Pros - no power bill
Cons- Only works when there's wind and sometimes when you need it the most there is no wind. I.e. the dog days of summer.Can be more expensive to buy than a electric powered compressor.

Electric compressor: Pros- will run even when there is no wind.
Cons: Need power source, although air lines can be run up to 5000 feet. Need shelter for compressor.

Paddlewheels mostly aerate surface water, aren't cheap to run, prone to parts failure and usually limited to shallow aquaculture ponds.

Someone out there has windmills that switch to electric if wind is not sufficient and back to wind when it is. Not sure where I saw them.

Aeration is needed to avoid fishkills following several cloudy, windless/calm days in the dog days of Summer. That's precisely when a windmill will not be working, per Cecil.

The best use for a windmill is for energy production, and storage.

The US is mapped out with wind charts, and the best methodology is to produce electricity, then utilize other methods of getting the work done based on what can be produced and stored.

You have to work within the limits.

Phil,

You do realize we're not talking about the power generating windmills right?

More Pros of electric are: A. it will almost always move and mix more water volume per hour than windmill i.e. stronger mixing, B. electric compressors are almost always easier, more convenient to maintain, repair, C. Electric compressors usually require less inspection and few repairs compared to windmills. I find electric compressors cheaper to repair than windmills.

The deeper a diffuser is in a pond the more wind speed it takes to create enough pressure and get a diffuser operating. Thus a diffuser at 5 ft will operate in a much slower wind speed compared to that same diffuser placed at 10'-12' & then 14ft deep.

Some of the newer style electric compressors have more efficient motors and operate more hours per kw of electricity.

Can you show me some?

A windmill uses wind? Correct? They create power based on wind? Correct? What may be a good way to control and utilize this power?

Also, a windmill *should* be taller than the trees near it for optimum use of the available wind. The taller the tower, the more $$.

No fairy dust here. We're talking about windmills that produce compressed air via a diaphragm not electicity. Two different animals.

If I understand JKB correctly, he's not suggesting that windmills can't be used for aeration, rather he's commenting on the most efficient means by which they may do so.

I think windmill aeration often conjures up mental images of the windmill rotor coupled directly to the compressor itself, which naturally means that the comp. doesn't run when the wind doesn't blow.

My understanding of JKB's comments suggests that it is more efficient to add another step into the mix......use the windmill to generate electricity, then use the electricity to power the aeration compressor, in a more-or-less traditional means.

To me, that does appear to offer some advantages over a direct-coupled compressor, namely that the electricity produced could be stored for later use, or perhaps times when the wind wasn't blowing. It would be more consistent also, in that the power output to the comp. could be regulated much more closely when compared to a mechanical, wind driven power system.

Wind power has been used to drive mechanical systems before....water pumps, grain mills, feed grinders, generators, even washing machines. In most areas that I am familiar with, all of those systems have been replaced by a more efficient source of power....save one. Electrical power generation still remains the most practical means of harnessing the wind.

Originally Posted By: Bill Cody

Some of the newer style electric compressors have more efficient motors and operate more hours per kw of electricity.

JKB
Can you show me some?
Newer efficient type motors are being developed by motor manufacturers. My main example is with the GAST 0523 rotary vane compressor. Originally the 0523 was the GAST0523-101Q-G582DX (1/3hp), then several years ago GAST switched the motor on this rotary vane to a 1/4hp dual voltage (0523-101Q- SG588DX) that ran more efficiently and produced the same air output as the old 1/3hp 582DX.

snakebite asks: I'm going to be on limited budget, if I have multiple ponds 5-6 when finished within close proximity to each other. Ranging from .25-up to 2.5 acres. Mostly flat bottoms 6-16 max depths. What's the most cost effective way of getting air into the multiple ponds? Bill what's the average cost of running a electric system per year? Is it running all summer/fall or just turned on in the evening into morning? Thanks.
When on a limited budget, at least for me, means that I have more time than money. With that philosophy then one can spend some time searching for the best motor deal and creating a do-it-yourself electric aerator or windmill. I have always specialized in DIY aeration. Good DIY very good electric aerators can be assembled for 1/4-1/3 the cost of a windmill. Research windmill costs and you will get an idea of dollar amounts. I have had one or two guys near me create their own windmill, either by buying the head and fabing it to an old style tower or building the head from scratch since he worked for a metal fab company. Often when one goes that route calculating the time involved results in more money than if the unit was purchased outright. Basically it amounts to what is one's time worth and how creative and talented are you?.

Electric aerators can be created using various methods and components as evidenced here by RC51's example. However I contend that his compressor is the weakest link in his system. However to do this one has to be handy, creative, and resourceful. I have been "toying" with various aeration systems since the late 1980's and have learned and still learning a lot about DIY aeration systems. My philosophy has always been if you are going to build a DIY make as good if not better than the commercial units. Many of the parts are basic available parts. With commercial units, you are paying for someone else doing good research, putting something together that is reliable, serviceable, does the task, looks good, and with a guarantee, plus it saves you a lot of time exploring what is needed, searching for parts, and assembling those parts. Many find this way too complicated. This can be time consuming.

The main and most important component in my opinion is the compressor. You want one that is durable, long lasting, and produces as much air and at least the same psi as the commercial units for your application.

The other part of the question is aerator run time. This all depends on numerous pond variables. My general rule of thumb is the higher average temperature of the pond the more the aerator needs to operate. Simple example: in Florida one may need to operate the aerator 12-16-24 hrs a day, in TN 10-16-24 hrs a day and in OH 4-10hrs a day. Various pond conditions have a big, big influence on the runtime of aerators. This is why one needs a very long lasting, very dependable compressor to withstand the long hours of operation between pump rebuilds. The default guidance is run aerator 24-7 to reduce chances of mistakes and unexpected weather events and to make up for your lack of daily pond observence. Cost of operating is based on amps of motor and electric utility rates.

Snakebite, one way I am "experimenting" with aeration is to start out keeping the cost low.

If your pond is not over about 10' deep, a linear diaphragm pump and a single or dual diffuser is a cheap way to get started. The pros will probably tell you these type pumps do not have the reliability of the rocking piston or vane pumps and they are probably right. But their one advantage is they operate on very low electrical current draw. If you are on a tight budget, it is not uncommon at all to figure the energy costs of one of the top of the line systems of 30 to 80 dollars a month to run them. The larger linear pumps run on about what a single 100 watt light bulb costs to run. Edit: with significantly lower cfm output - I wanted to make sure I was not comparing apples to oranges. Might take three of the linear diaphram pumps (depending on depth) to equal a rocking piston or rotary vane pump output.

They are probably not the ultimate solution, and maybe not even a long term solution, but the initial cost is reasonable and the operating cost is reasonable. Rebuild kits also seem reasonable.

I'll give you a link to the pump I started out with and the limited time I ran it last fall it worked fine with a double Matala 9" disk diffuser. Seemed to do a good job to me of moving a lot of water.

One key thing with these type pumps. They put out boo-koo air at shallow depths but if you look at a chart fall on their face with depth. The manual says 11.5' max depth but it would be almost stalled out at that depth and put out very little air. I have mine at 9' and 10' would be maxing it out in my opinion. 8' would put out a lot more air. So if you are going to have deep ponds, not the answer.

In one of my old posts somewhere on Pond Boss forum I put a chart that shows the air flow for the different depths.

Here is the old post that has links to the pump, a graph of output, and a link to the diffuser I used. Old post about Pondmaster 100

Also read the posts above this link to learn about depth pressure and sizing diffuser with pump.

Pondmaster 100

I was dead set on putting a windmill up. Had it narrowed down between two different mfg's. Then started doing some cost comparison and came up with the conclusion that if I bought an electric pump system that kept energy costs reasonable, with the lower cost of the initial system cost I could buy electricity for years before the free wind cost would be cheaper. All the while of being able to flick on a switch when I needed aeration most, if the wind was blowing or not.

I actually am going to use three of these pumps with three double diffusers on my 3.5 acre pond. Three pumps gives me the flexibility of only running one, two or three as I deem needed. I don't have to run a big single pump if I only need a little aeration in the spring or fall. What I am guessing I will give up is the durability and trouble free long time life of buying a commercial top end system.

Here is my reasoning. I am putting in top quality diffusers and lines going to them. Only the pumps are cheap (give under $150 each for mine, just do a web search). If after a year or two of operation I feel like it was a mistake, I'm out $450 for the three pumps. All the lines and diffusers will still be there ready for any pump I want to use. Or maybe I'll get tired of the whole project and forget it all. I will install the lines and diffusers in such a way so at any time I can go to a high end system or even wind mill if I should ever want. I still like the aesthetics of a wind mill, and may do it for that reason only at some point in the future to supplement the electric.

So for a reasonable cost I can experiment, yet still have things in place so I can easily upgrade the system at any future point.

This is a DIY project. I will not have a company rep or dealer to hold my hand along the way. If I stumble and fall, I have to pick myself up. But 40+ years of farming and working on and operating equipment plus a fully equipped shop and service truck makes me pretty handy when it comes to projects. Not everyone has that available.

One other thing to look at is the diffusers. Finer bubbles are better for moving water to the surface, (more volume of water is moved). Coarser bubbles are better for keeping an open hole in the winter if ice and snow will be a problem.

You can under aerate, make sure you have enough water volume "turns" per day for your BOW.

Just remember that air volume is your friend, and the smaller the tubing diameter, the less volume you will have because of restrictions.

I'd run inexpensive poly line under ground, and at the waters edge, put a manifold box with ball valves going to the diffusers, and run self-sink air lines in the pond that were 1/2" i.d. Underground, I think the lines should be 1/2" i.e for under 300' run, 3/4" for 300'-700', and go right to 1 1/4" for longer than that. I'd run black poly underground, with the least amount of connections as possible. When connecting pieces together, barbed fittings AND stainless steel hose clamps, or a copper/brass crimped band over the fitting. Poly pipe expands and contracts with temp, and it does that over it's length too. I've had fittings pull apart when running water underground. Most of my problems showed up in the Spring with the underground poly pipe, contraction due to cold, freezing weather I believe.

Bill, I live in east Texas and our summers are hot day and night. It would not be uncommon for a night time low to be in the mid 80's in July-September. Would there be any advantage in using a multi-timer and running the compressor two hours on and two hours off around the clock?
Tom Sterling

S County aka Tom - in your situation you are better off with the longer aerator run times especially if the system is not over sized. Correct size or undersizing requires long run times often 24/7. Longer run times become even more important if the pond has higher BOD, low transparency, high amounts of bottom muck, or medium to higher fertility; all requiring and benefitting from longer daily bottom to top mixing.

Here is my "take" about on & off shorter period operation. I prefer continuous run for the daily run period (4-18hrs) vs a few or several short periods of on&off. This is why. When the aerator starts up it starts mixing the water column from the diffuser outward to the edges, with water generally traveling & following the bottom contour an then into the upwelling diffuser. As the unit runs it gradually mixes and incorporates more and more of the "middle" water thus building on the energy moving water momentum. When the aerator is shut off 'early' in this process. All this moving water momentum is lost and a has to be recreated when the aerator is restarted. Restarting is less of a problem when the aerator is OVER sized and mixing currents are strong-voluminous based on pond size or volume; thus to create a complete turnover is a relatively short period of time.

Once you get the turnover started, IMO keep it going so more 'middle' pond water gets incorporated until you get at least one complete turnover, not just a turnover or water movement around the edges and across the bottom.

No Bill, they did not make a better motor for these, nor will it ever happen. The current 1/4hp motor is ~35% efficient. The 1/3hp rig was between 40%-43% efficient depending on the motor manufacturer.

Either they oversized the motor or improved the pump, but no motor efficiency improvements here with the 1/4hp rig.

Scott and I were discussing this last week on his rig, and I had a nice chat with the engineers at Gast. SOL on improving anything with the canned motors. Just pay the electric bill

Cody note - I was just repeating the explanation that I received when they switched motors on the 0523 rotary vane. The salesman probably had his info incorrect. Did you ever know of a salesman that provided bad info?

JKB note - Bill, they changed the motors to the 1/4hp rig over 10 years ago. Yes, never rely a salesman!

Here's a pretty graphic representation of the differences between an electric compressor powered diffuser and a windmill powered diffuser. Where you see the dark ice covered with snow, that is the hole that the windmill powered diffuser had open on Monday. Today is Wednesday. The hole that the electric compressor has open is about 30'-40' in diameter, the hole that the windmill had open is about half that size.

Diffusers are in 4' to 5' of water. Temperatures lately have been in the low single digits at night, and barely breaking into double digits during the day. Virtually no wind yesterday, 5-10 mph wind today, but the windmill is within 40'-50' of trees that are taller than it is. The trees are to the East of the windmill, it has a clear shot (no trees) of about 500-800 feet to the North and to the West of the windmill. To the south the closest tree is about 80' and is as tall or taller than the windmill.

That's a good question. There are not doubt pros and cons of each way. Often it is not practical to oversize an aerator for larger water bodies.

^ moved ^

And I have a good answer. Just not sure how to post it to this audience?

Thursday both diffusers had open holes. Last night it was -8°F and relatively calm. Today there was clear ice where the windmill diffuser is, and I could see a very large air bubble under the ice at 11:00 a.m. It still hadn't "popped" by 2:30 p.m. We are having steady 20 mph winds now, with gusts to 40. Temps are in the upper teens. I'll see tomorrow if it opened up.

Scott how about shooting a hole into your bubble? The shotgun pellets or bullet shouldn't penetrate far enough into the water to do any damage to the diffuser.

The thought crossed my mind but I didn't want to waste an expensive self defense bullet on the test (9mm Hornady Critical Duty). The angle that I'd be shooting from also would put the bullet away from the diffuser. In all honesty, I doubt that a diffuser that was covered with more than 12" of water would get damaged by anything other than ball or FMJ ammo.

No shotgun?

No, I usually don't carry a shotgun when visiting clients places, but either the 9mm or .45 goes along for the ride. Concealed carry means that you aren't supposed to see it.

I don't, but here's something to consider:

If you don't have both ponds full of water now, you will have to bleed off excess air. That will result in higher energy costs until you get the 2nd pond completed vs. running a smaller compressor at each pond. Also, you have all your eggs in one basket so to speak. If the compressor were to fail, both ponds would be affected.

You will definately have to have a manifold near the compressor to direct air to each pond, then another manifold at each pond to direct air to the different diffusers in each pond.

Running one larger compressor is much more energy efficient than multiple smaller ones. The smaller the motor, the more it eats and is much, much less energy efficient.

The answer to "add a pond at a later date" with an initially larger compressor that is on line voltage is fairly complex if energy efficiency is the goal.

The entire system, including future expansion, needs to be laid out up front and careful consideration is paid to all of the components, especially the compressor and motor.

It seems unlikely that you will be able to come up with a rig on line voltage that will satisfy both conditions with only a sweet spot window of 20%. (motor load efficiency window)

I mentioned this was fairly complex if energy efficiency is involved.

Personally, I would not go this rout with a pump on line voltage, nor would I ever consider multiple smaller pumps.

Given the effeciency of the motors used in today's aeration systems, would one 3/4 hp compressor be less expensive to run than two 1/3 hp compressors? (if the pond depth and number of turns warranted that sized compressor)

If one pond is completed now, and the 2nd pond won't be completed for a year, I don't know if all the air from the larger compressor would be needed, so the excess would be bled off. I suppose the only way to know for sure is to run the numbers on cost of operating. If the 2nd pond wasn't going to be built for another year, then that's one year of operating expense that wouldn't be needed if two compressors were used. Just saying.........

How about a simple formula of: Buy a unit that does one pond. When the second pond is built consider a larger one that does two. Then, use the first unit on the third pond that is needed to make use of that pump. After all, don't we just want excuses to keep building ponds. Of course this all grows exponentially. When you get the third pond, get a compressor that does all three ponds. Then build three more ponds, one for the first compressor you bought and then two more ponds for that extra compressor you have. Now we are up to six ponds. I have to stop there, JKB will need to help me with more math than that.

All kidding aside, it might be better to just buy what you need. That second pond may take longer to get to than expected, which then adds to un-needed costs from overbuying. I just wish that I was in a planning stage for aeration myself. I'm jealous.

I have no further comment on this subject.