Pond Boss Forums AERATION Systems questions How to clean bottom without dredging?

I have a farm pond that is 20 years old. Pond is small, only half an acre, but productive and healthy. I bought the property with the pond on it 10 years ago. The pond has never been dredged. I am thinking of installing a windmill bottom aerator as I have heard this will clear the sludge on the bottom by stirring it up and letting the bacteria consume it. I have just discuover this great site and the wonderful advice. Appreciate any and all opinions.

Thanks!

Here's more info on my pond. It's about 6 ft deep in the center now. I have walked through it when the water level was down and sunk up to my knees almost in muck. The pond is spring fed and also fed from runoff from a larger pond. I have lots of geese and get loads of goose droppings. I often wonder if the muck is not mostly accumulated goose droppings from years of their "patronage". Appreciate all the info that you have provided thus far. I saw that a windmill aerator was a "last choice". Why would that be, are they just not reliable enough because of the uncetainties of wind?
nhman

Be very careful! You can kill your fish! There are toxic gases on the bottom of your pond. Even a bottom aerator can cause problems. Winter will be the best time to dredge as oxygen levels will be at their highest. There are professionals on this site that can give you guidelines. Greg Grimes has a lot of experience with bottom aerators. Even if you decide to dredge your pond a bottom aerator would help prevent future problems. Bob Lusk and others have either assisted or done this type of work. Good Luck!

nhman,If your pond is productive and healthy you should not have a lot of sludge/buildup in bottom.If you do then it can be more productive and healthier. There are many posts on here from Bill Cody and Greg Grimes on this topic, you may want to plud those names into a search at the top of this page. My 2 cents would be to add aeration as a single diffuser system (1.5) CFM would probably do the job.Here in Ohio I see a sludge (septic) reversal of about 4-6 inches per year if I can hold my DO level at 70-80 % of saturation from April to November.Dredging is costly and messy and unless you need depth beyond original hard bottom I would not do it.If and when you install an aeration system follow the startup instruction for your situation and you will be OK. I would only use a windmill aerator as a LAST resort. If you can get electric within a few thousand feet of your pond install an electric unit as you can pump air a long distance. A windmill in my opinion is always a last resort,again see the many posts on this subject."Good Luck"

Ted Lea, I had not thought it possible to push measurable amounts of air that far. Just hadn't considered it. Are there any factors like size of line or HP of compressor?

You can push air a great distance, bottom aeration may not do the job depending on what silt load is on bottom. If you plan on using the pond for fishing, recreation and swimming . Drain the pond clean it out and restart it. Less headaches in the future and you will spend more money trying to correct nutrient problems in the future and not get the results you want.
A half acre pond will take a good blade man two days at the most to carve out at the same time you can structure and fix any other future problems and make your enjoyment life long.

nhman,Do you know how much sediment or muck you have (approx) your "silt" load wont change much as Scott states as "silt" is usually wind or erosion driven.However even with your pond cleaned out with dozer you will still need an aeration sysytem or the "fill in" process starts all over.You can install structure from shore or here in Ohio we do a lot of it on the ice. Back to your question,I have installed Vertex Air One systems 2000 feet away from pond,supplied 1.5 CFM to 12 feet of water and had over 1CFM at the diffuser (Coactive Airstation) and turned over 2700 gallon of water per minute (thats a lot of water)The hose size was 1/2 inch ID on shore and .55 ID (Bottomline weighted tubing) in the water.For more information on Vertex visit their web page at vertexwaterfeatures.com as with the specifics of your pond you can obtain the exact specs for your pond. This is where diffuser selection becomes very important as most require more CFM to turnover lots less gallons.Ted

One additional thing,and why it is important to have all your numbers on pond. Lets say your pond is 1/2 acre and ave is 12 ft. Here in Ohio we want to turn the pond over as much as twice per day (small ponds).At 12feet and 1/2 acre figure you have just under 2 million gallon of water.Now how much water will a diffuser turnover at a given depth at a given CFM ??? I use tested diffusers that I know exactly how much air it takes at a given depth. The above example would tell me that my diffuser will need to turn approx 2700-2800 gallon per minute to turn the pond over twice in 24 hours.In your situation you may not want or need that much turnover so you may operate it just in the nite hours.Warm water fish cold water fish nutrient load etc etc all come into play.This is also why windmills are kind of a shotgun approach to proper aeration. They have a place but I work on a lot of ponds in July with 1PPM DO or less that have windmills that have not turned for days.I have also replaced a lot of the Airstones that I believe are approx 500 GPM at best with a good rubber membrane diffuser so that when the pump is working you are much more efficient.One GREAT thing about this site is all the opinions that you will get,read them all as there is such a wealth of knowledge here, Ted

Ted:

Since I am debating between a windmill aerator and electric, I thought I'd join in on this. Basically, I have no pwer of my own near my pond. the guy I bought it from has a machine shop about 2-3,000 feet waya that I may ask if I could use his power and help pay the increase in the electric bill any electric compressor would generate. What is the longets sucessful distance I can run an air hose to the pond and into the diffuser that you are aware of? My pond is 1.75 acres large. It is l-shaped. It has a lot of muck and is an old pond like nhman. Do I need two disffusers? can I run both off of the same pump? How much more in electricyt would I be bumping up my neighbor's bill? Maybe too tough of questions to answer but I thought I would try.
Do aerators really eliminate the muck?

Mark C. Running air lines 2000 ft are no problem if done correctly.You could also run a 10 or 12/2 with ground 1000 feet without much voltage drop and get power that much closer. For your 1.75 acre pond run two 1/2 or 5/8 ID lines to the waters edge.Use 1/2 inch ID for the hose in the pond With a 1/4 HP pump that produces 3.6 CFM @ 10 psi you will have plenty of air to supply 2 Vertex Coactive Air stations. A Vertex Air 2 is supplied with two valves and everything you would need. This common pump will do this for a cost of about .75 cents per day @ .07 cents per KW of power.Look in on the vertexwaterfeatures web page for more details.My Web people tell me our site should be complete this week and I have a lot of information on this and other units.Feel free to send me a line at talea@thewavz.com
if we can be of service.And yes they will restore your ponds bottom (eliminate muck)aerobic bacteria do amazing things. If you find that a windmill is more suiting I would still install a Coactive Air station on it. If you consider the new higher CFM Koender windmill or the original 1.5 CFM model keep in mind that the diffuser is the key and that when the wind "aint blow'n" zero times zero is zero perhaps when you need it most no matter what type of diffuser you have.Ted

Ted, whats the voltage and amp draw on that compresser ?

Thanks, Ted. I will keep a watch on that website. I want to know more and take it from there. If my neighbor balks at tapping into his power, I will seek your advice, and if the price is right, purchase a windwmill setup from you with the understanding that if the wind ain't blowing, the process stops for awhile. The good news? When there isn't a breeze or wind blowing at my pond's location, it ain't blowing within 30 miles of the area. It is very wide open, it seems to funnel any kind of weather pattern through it, and can pick up wind from every direction. I have to believe windmill aeration, despite the bad rap it gets, has to be better than no aeration. I need my pond cleaned up one way or the other. Thanks.

Mark

Ken the voltage is optional 115 or 220 the amp draw is 4.6 on low volt Mark C. Yes some aeration is better than none I agree. You should be able to find a windmill from one of the suppliers listed in the Resource Guide on PondBoss as I do not sell them. We do however convert a lot of them from the small airstone supplied, Good luck Ted

Ok, Ted. I am aware of those resources but wanted to throw some business your way if I could. So, that leads to a couple of questions. Why don't you sell them? And, is there one you can recommend over another or(to avoid any criticisms from PB members who do sell these), do some have features/specifications/air stones/CFMs, etc. that I should consider between the various brands of 'mills that could give me the best success possible if I HAVE to go that route? Again, I am going to bribe my neighbor with a bottle of his favorite Merlot into letting me tap into his juice for an electric aerator, but if that fails, I want the best choice out of the alternative. Again, I need to go with two diffusers. You can e-mail me directly if you prefer.

Mark

well before anybody goes buys wire and puts it 20" deep , just a thought. when running wire long distances your main concern is voltage drop and motor start up amps, along with running amps. always talk to a qualified electrican before running electric wire any long distance for proper sizing and safety . theres lot more to the job then just burying wire .

Mark C,
I think Bill Cody sells windmills.

Mark, Appreciate the business but the reason I do not sell them is that they do not do what I need them to do for my customers.Its a great concept "free air" but one needs control over how much air and when.Nothing worse than a hot August day no wind and DO levels sinking past 3-4 PPM,its a terrible feeling to see money invested in a windmill with the pond owner having great expectations and you have to tell him he needs to make the wind blow.I prefer to market results and I have not seen that with the mills.I will also tell you that the average pond owner that I have delt with that owns a windmill does not understand his pond and its needs.He saw a mill by a pond and figured it would do the job. The mills are a great visual sales tool. I tell my customers if you want to aerate then aerate and if you want to know which way the wind is blowing then a mill will do that.I have done many DO tests in windmill ponds that had a tough time maintaining 30 40 % of saturation at for example 26 C or 79 F which at sea level in fresh water would be 8.1 PPM DO o 2.5/ 3.5 PPM DO. (not good) most of the time.I have a Koender 1.5 CFM on a 20 ft tower with the original air stone and a Co active airstation valved so that I can switch from stone to station.I use this in one of our display ponds. I like the stone for winter operation as it turns very little water.When there is a situation (no power) then yes they are better than nothing but I have always managed to trench power or air lines to accomodate.Not sure the cost between the old style original mill and the new twin but Im sure the old 1.5 CFM with a Air station will out perform the new style with a stone or any other rubber membrane difusser.I would advise buying one from someone you trust, has parts and a good freight rate and lastly a good price as most of them are priced close together. I would buy one with the airstone and use that as my shallow winter diffuser if ice cover is a concern.Just manifold in an extra valve. If it is not a concern then they make great paper weights and I have a big box of them as we offer a conversion kit for the mills and have replaced many.(sorry bout the long reply)

Thank you. Your response is very helpful.