Pond Boss Forums AERATION Systems questions Air diffuser selection

Eastland, that sounds like solar power will be a winner. I have thought about it a lot. It may work for part time aeration of a small pond, but until solar panels drop significantly in price, or electricity skyrockets even more than it is(it probably will), ($65 oil) it is wishful thinking.

Facts: a 1 acre pond needs a compressor dwawing 3-4 amps from 115vac. That is 400 watts. Assuming 100% efficiency from an inverter, batteries have to supply 30 amps. If it is run for 10 hrs, that is 300 amp hours of batteries.
This would be if aeration at night. It would take 500 watts of panels to recharge batteries for 10 hrs. A tall order and extremely expensive.
A DC compressor would insure more efficiency, but still similar panel and battery requirements.

ML, I think you are out of luck with your size ponds unless he is working on a nuke project.

Burgermeister, Eastland just might pull it off.

He once posted something about some thangamajigs that he had picked up at surplus, put them in a series and I believe created power. Maybe he can elaborate on it.

Also, he is in West Texas and butt deep in sunshine. Just give him a big magnifying glass and a couple of mirrors and he could get spooky.

Here's a related question for you all. As mentioned on some other threads I have a FA and a duckweed problem in my pond. This year I have been pumping my pond water through the bog to take some of this out and I have added some bacteria. I have less duck weed this year than most but I still have one section of pond totally covered with duckweek. My pond is two sections separate by a narrow channel. The prevailing winds blow all duck weed to one end of pond. For a month now one end of pond has been totally covered very thick. What do you think this does for oxygen level in pond especially when you consider that it appears that my bottom diffuser is not putting any significant amount of air into the water. One would think a total surface covering would drastically inhibit oxygen uptake from the surface. I have not had any fish die off nor any hint of oxygen shortage. Any experience or theories on this out there?

bz,
Just a seat of the pants theory. Duckweed is a plant. Plants produce oxygen. How much and whether it makes up for covering the water? I couldn't guess.Maybe someone that has an answer or educated guess will respond.

BZ :

As soon as you can without causing a DO crash by spraying the duckweed in hot weather get it out of your pond. Duckweed thrives in still low O2 water with nutrients. It is very hard to get rid of and causes DO problems as follows. Because duckweed covers the surface it blocks all light from the plankton base in the water. The plankton is a much better source of O2{as well as food} for the pond than duckweed. In addition all the other beneficial functions that light causes in the pond are restricted by duckweed. Thick duckweed layers also inhibit the exchange of O2 to the pond surface waters and the exchange out of the pond waters of CO2 and methane gases from bottom decay.

One good point any active water movement by waves, aeration , sprayers etc will help reduce duckweed by the constant turning over of the plant so that its roots are exposed to air and light and are out of the water. ewest

bz,

I had a 100% coverage of duckweed and tried to experiment for 2 years after I bought the place. The pond would not support desireable fish. Aeration alone did not even put a dent in it. Stocked with bluegill to see what would happen. Bluegill died several weeks later. Scraped it off the surface. Had 100% coverage in about 2 weeks and one sore back. Bullhead, green sunfish and crappie were the only fish to survive. Pond was 11 feet max.

This spring I did the unthinkable. I added sonar and larger aerator. I did not want to use chemicals but this was the last straw. Also added triploid carp for the just in case along with bacteria. Early on I had a tea colored water. No duckweed or watermeal except for small amounts along the shore lines. This pond had not seen a "bloom" in years. Many years according to neighbors. It took a month and I had a beautiful green bloom. So I added fish. Non have come afloat yet. My bloom has been maintained all year so far. Before when you could get past the duckweed the water was a black color and nasty smelling. I am now in a dry year and I have 12.5 foot depth. Moral of the story is to get rid of the duckweed however you can if you get major coverage.

ewest:

Does this hold true for floating algae too? I have both. Although I use Reward/Cutrine+ and mechanically remove as much as I can, it is a big job. We try to keep the coverage below 30% of the surface area. It appears the floating algae is keeping the duckweed somewhat under control.

Part II:
My pond is 1/2 ac.(6' deepest) and I add well water almost daily through two venturi injectors. Some are suggesting surface aeration in a shallow pond is better. Any comments?

These are interesting responses especially Aaronhome who has lost some fish under similar circumstances. I know that my pond has high nutrients because it never had any duck week prior to adding fish. The pond was empty for 3 years before stocking and I had some but never a lot of DW. Each year after adding fish the FA and DW problem has gotten worse. I’m guessing it’s all the added nutrients but I’ve never found a convenient water test kit to actually measure levels. My pond is only 1/2 acre and in most years I keep the pond 2/3 open by skimming them off manually. I’ve been busy this year and lost control. Here’s the funny part. I have never before nor do I currently have any signs of an algae bloom or a DO problem. My water has a tea color because of the bog it comes from but it is otherwise very clear. So it’s weird that I appear to have lots of nutrients and even when there are no surface coverings of weeds I still never get any suspended algae. Plenty of FA and DW and I do get some rooted plants growing in less than 2 feet of water. Perhaps my lack of algae is due to the water color, I’ve never done a sechi disc reading but my guess would be about 18 inches. Despite having a load of DW on the surface in late summer and what appears to be a total lack of suspended algae my fish are healthy, rarely refuse to eat, never found gulping air, and generally are doing very well. I also think I have way over what would be considered an acceptable amount of fish. I have no fresh source of water for pond other than rain. This year has been a unique experiment in that the small end of my pond has been 100% covered for a month. Still no fish problems, maybe they all moved to other end of pond? I don’t think so cause if I make an opening in the DW and throw in some feed they start hitting it immediately. I do have a bottom diffuser in 6 feet of water on same end of pond. But according to what we’ve all said on this thread the bottom diffuser can’t be saving my fish can it? I only run the diffuser 8 hours per day. This whole aeration question is critical to me since I seem to have some conditions that would make my pond ripe for fish kill and I don’t understand why I haven’t had one yet. So I’m trying to figure out where my oxygen is coming from so I can do whatever it takes to help it along. That’s why I originally asked about the best way to aerate. I think my pond is accidentally working and I don't know why.

bz,
I would be wondering the same.
Remember the aeration mixes the water. Maybe there is enough open water for the aerator to do it's job?
Wouldn't the water under the DW be oxygenated by the aerator?

Ric, good thought. I only run the aerator 8 hours a day and the DW is so thick that it only opens up about a 10 foot diameter hole which closes as soon as the aerator goes off. Maybe this is enough open water to do the job?

tecman and bz :

Sorry it took a while to get back to this thread.

tecman.
There are many types of algae from planktonic types which are good to giant lyngbya which is one of the worst types of pond plants that exists in the US. The filamentous algae {FA} of which giant lyngbya is a type are a problem. You can find much on the forum about FA which I will not go into here. The more serious types of FA can indeed cause the same type of light blocking and DO problems as duckweed. While DW is a problem when it gets out of hand it is easier to control in low densities than some of the FA types. I am not an areation expert but I do think it is very helpful for ponds when done correctly. I read the same posts on the subject and think that it does improve DO levels and water quality over time. Anything that disturbs the water surface or causes waves will help control DW. I recomend manual removal of weeds as the best method of control but realize that you are treating the symptom not the problem which is some combonation of nutrients ,light and water quality. Others on the forum can answer your question on surface areation vs bottom type better than me but areation is bound to help.

bz
Your areation is I bet helping you avoid problems and may be saving your fish. While DW and FA thrive in acid waters most plankton does not. Do you know your alka., is your pond acidic being part of a bog ? You described tanic colored water which is often clear and acidic and lacks a plankton bloom. If that is your condition lime might help start a bloom and help shade out some of the FA. Plankton also adds oxygen. You might try running the areator longer in conjuncton with manual removal of as much of the DW and FA as you can get out as trial run to see what happens.

Ric
The areation under the DW would help as noted above and with DO but not nearly as much as if the water were also exposed to the surface along with areation. The DW inhibits water contact with surface air and thus oxygen absorption.

ewest

Ewest, thanks for the response and suggestions. You are correct that bog water tends to be acidic. I do lime the pond at least twice a year. Just checked acidity about a month ago and it was 6.5, not too bad. My pond is only 100 feet wide at it widest and I lime it using dolemite lime using a spreader on back of tractor. In the winter I spread the lime on the ice over the entire pond surface by driving right out there and covering the whole thing. Then at least once in the summer I back the tractor up to pond edge all around and let her fly. I can reach about 25 feet out from shore this way. I also had a pond management company do a water test 3 years ago and they had no recommendations other than at that time it had low nutrients. I suppose I should test it again but I'm betting the fish have added a lot of nutrients hence the DW that I never had before. So if it's not acidity keeping me from having a bloom got any other thoughts?

BZ :

Did the report on nutrients say which ones were lacking. If you have alka. of at least 20ppm then the lack of a bloom should be from lack of one of the required nutrients. If you get PB mag. there is an article in one of the recent ones on fert. that describes using small containers to take water samples and adding as best I recall nit. to one, phops. to one etc. and by the reaction you see what is missing. That might be a way to do your on test without impacting the pond until you know. Good luck. ewest

Ewest, thanks again for response. I'll give you what the water test showed. PH=6.5, total hardness=102, total alkalinity=102, total ammonia=1.3, levels of N, P, and K were not measurable. These tests were done when the pond was about a year old, no fish, no aerator. I ran the aerator for a whole summer before adding fish to take ammonia out. The only things they recommended was some lime to try to get to PH=7.0 and the report says if pond is new and fish are not fed to add some 10-34-0 fertilizer. Thanks for any more thoughts on this.

BZ:

It sounds like you could use a few balanced nutrients. But I would be reluctant to do that with weeds in the pond. I would try 2 things : 1--read the referenced PB article and see if those test methods will help you-- 2 I would get some current soil samples from several locations in the pond bottom and get them tested for pond nutrients. If you can keep your weeds under control this summer and find out the reasons then you can work on it over the fall and winter. In my opinion adding fert. this late in the growing season is not something to guess about with weeds in the pond. You could make your problem worse. ewest

Ewest, remember that this test was done before I ever stocked with fish and also at that time I never had more DW than a little around the edges. So I too concluded lack of nutrients early on but I think I must have more than I need now because 3 years after stocking fish the FA and DW has gone wild. I have looked for an inexpensive nutrient test kit so I could verify but just like the other thread on DO meters I haven't found any good advice on nutrient testing. I suspect a test will now show lots of nutrients so my question is why no suspended algae, just FA and DW? I do have some inexpensive soil tests kits that I use to test food plot soil. Question is, can you use these to test water?

BZ :

I take soil samples from the bottom of the pond using small dia. pvc pipe. Jam it in bottom and dig out sample. Get a number of samples from around pond. Our Coop. Ext. Service will take the samples when dry and test them for pond use and give a report. The cost last I checked was $ 6 . The soil test will tell what is missing and agent can tell why no plankton bloom. ewest

Thanks again Ewest, I'll check out my county extension office. Never even thought of that since they really weren't much help when I built the pond. There isn't a lot of pondmeistering going on in Minnesota because of our harsh winters I suppose. So the local services aren't really geared to support that but maybe I'll be surprised.