Windmill powered air pump....

[Damon]

So is a crankshaft like that something I can buy with bearings and then cut and weld?  Or is it fairly simple to piece together with some components from Graingers?  I'm more of an electrical guy and not as familiar with where to source mechanical assemblies.  I learn quick though! 

Think I could pick up some used airbags somewhere for a proof of concept?  If I could find some in a junkyard they'd probably be in bad shape but would at least let me mock things up.

[JRR]

I agree with pumping water directly.  If you lift the water several feet up ... and just dump it back into the lake, you'll get all the aeration you need ... especially if there is a bit of a breeze.  Modern plastic piston seals will last a very long time.

... for some related info:
http://www.aermotorwindmill.com/

[Damon]

I don't think just dumping the water back in would do much for aeration.  Even powered fountains spraying lots of water up and back down onto the water surface don't work as well as a diffuser.  Floating, or fountain aeration, typically only works for ponds 5-6' in depth and don't do much for thermal de-stratification.  Anything deeper requires diffused aeration while is much better at moving the entire water column.  This stirs up the bottom organic muck, gives the aerobic bacteria the oxygen they need to break down the muck, and also prevents winter fish kill from freezing over.  Fountains look great but don't really do what I need done.  This isn't a man-made pond manicured in an industrial park or golf course.  This is an old farm pond that drains hundreds of acres and needs to be reclaimed. 

[NM_Shooter]

Pumping air through an air stone is what I am hoping to accomplish. 

[Damon]

What's the size, depth, and condition of your pond?

[NM_Shooter]

What's the size, depth, and condition of your pond?

About 1.5 acres, 12' deep at the dam.  half of the pond is 5' deep or less.  Decent amount of weeds and bugs, covered with snow 4 months out of the year.  We have not had a winter kill in awhile, but it has happened.  The aeration is meant to try and keep the odd kill from happening during heavy snow years.  We also added ~800 trout to the pond last year, so the burden on the oxygen saturation is greater now.  We can't let the saturation fall below 4%, since it was rainbows that we stocked.  Brook trout can go to 2% and survive.

-f-

[peternap]

Have you considered a 12 volt electric pump driven by wind or solar? I'm certain you looked into it but just in case.......

[NM_Shooter]

Nah, I haven't.  I worry about solar being left out with all the snowmobile traffic we have.  Might consider it though.  The exercise with this project has been to get something in place that costs ~$200 or less using bailing wire, duct tape, and old newspaper.

[Damon]

You forgot bubble gum!  I'm looking for a cheap-ass DIY option as well.  Money is just too tight to blow $1K on a non-essential pond aerator. 

A 12V pump would work great for a small decorative or koi pond but they just don't have enough power to achieve the kind of aeration needed for a big pond.  Plus by the time you convert mechanical energy to electrical, your efficiency ends up lower than trying to directly drive a mechanical pump with kinetic wind energy.  Now I have seen solar setups but they are over $5K!!!  A 125watt solar panel alone is $700 and once you add a charge controller, inverter, AC pump, etc. it all starts to add up.

NM_Shooter - Sounds like you've got the makings of a helluva trout spot!  Is there a constant outflow of water from the pond?  I've heard that the blue or black pond dyes greatly decreases submersed and submerged weeds.  Since my spring dries up from June - Oct I'm going to dye it once it does which should help.  I've also stocked 12-14 grass carp (Triploid White Amur) that will gorge themselves on the weeds over the next several years.  They won't eat your trout either.  They can grow to 35-50lbs here in the Midwest but eat the most as adolescents (go figure).  I'm also going to grow some barley straw on the property, cut it down with the PTO mower, stuff it in onion bags, and anchor the bags in the pond.  Apparently as barley straw decomposes in water it functions as an algistat.  It won't kill existing algae but it releases something that prevents algae from growing in the first place.  So if you treat your pond in May and then again in July you can help keep the algae under control.  But doing this will increase the oxygen demand so the first step seems to ALWAYS be an aerator.  Oxygen is KEY in fish health, reduction of muck, release of nasty inorganic compounds, and preventing winter kill.

My plan = aerator + grass carp + barley straw + summer dye

Of course, the first and most important component is the most expensive!