Pond Boss Forums AERATION Systems questions Please help me design my aeration system

Yup, I’m another Pond Boss Forum newcomer seeking advice on aerating my pond! Hopefully I have something interesting to offer…

It’s a 2.2 ac manmade pond on a property my wife and I bought last winter. I paddled around on it with my fishing sonar and then played around with a graphics package this week to produce this contour map:

http://s829.photobucket.com/user/gbin2/media/Rabid%20Beaver%20Pond_zpsclcdlqkv.jpg.html

Those contour lines are right, it’s nowhere shallower than about 4 ft. Despite its size, it’s completely encircled by a stone/concrete block-walled bank. (Next year I plan to remove a span of the bank and make a beach as indicated on the map.) The folks who created the pond 30 years ago said they originally dug it to a depth of 20 ft, so presumably significant siltation has occurred since then, especially in the deepest part which is now only 14.5 ft.

I reckon the two most unusual things about the pond are that 1) it’s exceptionally clear for this area, with around 10 ft visibility most of the time (that’s why we bought the place! :^] ), and 2) we really want to keep it that way. It does have reproducing populations of bluegill and largemouth bass from these species having been stocked way back when, and I’m happy to have them, but maximizing fish production/fishing potential is not our top priority. What we want most is to maintain the pond for swimming, aesthetic beauty and wildlife, in that order. So we don’t have any fish feeders set up, and we try to minimize the nutrients reaching the pond in general.

Nonetheless more nutrients get in than we would like, as the pond is surrounded by quite a bit of mixed forest and I haven’t found any way to stop the great many leaves and pine needles from getting into the water. (I’ll probably start another thread on that topic in another message board here at Pond Boss shortly, so please don’t bother to address it here.)

At least it’s not farm fields! There are no springs in the pond so far as I’m aware – the former owners said they dug it where they did because there was a perpetual wet spot there, though – but the surrounding landscape drains to it by whatever means for quite a distance around, and that doubtless brings in plenty of nutrients as well.

We did have a free-floating algae bloom this summer that knocked visibility down substantially for a while. That’s partly why I want to add aeration, to shift conditions as much as I reasonably can toward favoring aquatic plants rather than algae and thereby help keep the water clear. (Right now just about the only “plant” growing in the pond is a thick carpet of the lightly rooted algae Chara, which we’re glad to have, but which I intend to augment with a carefully selected variety of aquatic plants that wildlife like and that don’t usually get too badly out of control.) I’d also like to do whatever I reasonably can to get rid of the muck that’s already been laid down in the pond short of dredging it, and presumably making the lower waters more aerobic will help with that. Swimming will be more pleasant without so much thermal stratification, too. Any benefit to the fish will just be a bonus.

So…

- What aerating equipment should I get? I don’t mind paying for high quality, be it in terms of performance, maintenance or durability. I’m not very big on DIY and would prefer a ready-made system, but I could probably put something together myself if that’s the only way to obtain high quality; I plan to do the installation myself, in any event.

- Where should I place the diffuser(s)? On this point, I should say that I’d rather go with only a single diffuser – or if multiple diffusers are truly necessary then only two instead of three – despite the pond’s size if that would do well enough in terms of the goals I stated above, as I and (especially) my wife are concerned that having the water roiling in multiple locations would detract a fair bit from the pond’s aesthetics. (We spend a lot of time just looking out at the water from the house or water’s edge. :^] ) Keep in mind, too, that as indicated on the map I intend to install a water jet under the dock to sweep across the planned beach and thereby help keep it clean; presumably that will help make up for relying on fewer diffusers than would ordinarily be used. Probably whatever system I buy or put together would also allow me to add one or two more diffusers in the future if I deem it absolutely necessary.

- I’m only looking at summer aeration at present, as the pond’s never experienced a winterkill and I’m not aware that winter aeration will really do anything to advance my goals. Do you agree? If not, could the same aeration system be used for both summer and winter purposes, just changing settings so that this diffuser is operating at this time and that one is operating at that time? In that case, where would you place the winter diffuser(s)?

- Last question for now: Does it make much difference where I put the compressor? All other things being equal, I’d much rather put it right by the barn, some ways away from the pond to minimize the clutter and noise down by the water. Again, aesthetics… Minimal noise level is one of those quality aspects I’m quite willing to pay for, by the way.

Thanks very much for any time and effort you put into considering my situation and advising me! I look forward to reading any and all thoughtful replies I receive, and I promise to give them serious thought in turn.

Gerry

Welcome to PBF gbin!

For turnkey aeration systems I recommend you check out the PB Resource section. Lots of good sources there for both design and equipment.

http://www.pondboss.com/resource_guide.asp?c=1

Again, welcome to PBF!

Bill D.

Thanks, Bill! I'm glad to be here!

I'm really hoping for a lot more specific advice than a link to a list of vendors, though, and I'm not insisting on a turnkey system (that's a great way to describe them, by the way) if I'd be better off putting together my own, either. And I looked over the vendors in the resource guide, and a few others I found online, before ever posting here.

See my (admittedly overlong) first post for the advice I'm actually seeking. Hopefully at least a few folks will find the time to offer such. I'd sure appreciate it!

I'm a lifelong Vikings fan and watched their game against the Eagles this afternoon. Ouch!

Gerry

Hey Gerry,

My apologies for not explaining why I recommended the Resource Guide. In your original post you stated "I’m not very big on DIY and would prefer a ready-made system." If you contact a company like Vertex, they will work with you using a satellite pic of your pond, your depth measurements, your goals, etc and custom design a turnkey aeration system specifically for you. They will size every component for your application, tell you exactly where to place each diffuser in your pond, etc.

Hopefully, some of the pros will chime in with their opinions....

Good luck!

I understand, Bill. Actually, doing just as you suggest was my first thought right after I made my contour map, but I was (and am) bothered by putting so much trust in even the finest company out there. They have a direct financial interest in the advice they dispense, after all. I'd much rather start out by getting grounded with more independent advice from folks with knowledge and experience such as I figure participate in this forum. And as I said, I'm not opposed to going the DIY route when there's persuasive reason to do so.

I'd be delighted to hear from pros here, but I'd be equally delighted to hear from others with knowledge and experience, too! So let's hear from you!...

Gerry

O.K. I had thought I answered this, but I have no idea where the post went to....

You have roughly 5.9 million gallons of water in the pond. You want to bring that volume of water to the surface at least once every 24 hr, if not twice. 2 diffusers stations can move that volume of water, but they have an area of influence too, so to cover the complete pond I'd like to see 3 diffusers stations, one in the deepest part and two more in 7-8 ft water depth. Take a look at the Vertex site, they have a chart for GPM moved per diffuser station.

Getting the pond aerated correctly will help reduce the amount of muck that builds up in the pond, and that is a goal for a swimming pond, right?

I would place a 1/2 hp compressor near the barn in a cabinet with sound deadening material lining it (Vertex has them), run 1" poly down to the pond edge to a remote manifold box, and run the weighted lines into the pond from there. I would get a remote manifold box that has extra outlets, and place 2 more diffusers in the pond in 5' of water, close enough to shore that if something went into the pond during the winter, it could get to shore to get out and not have to try to climb up on the ice to get out. Those diffusers would just be run in the winter. Switch off the deeper diffusers for the winter.

While you don't *have to* have winter aeration, bacteria to chew up muck works much faster when it has O2, and it will work even during the winter. You can also add bacteria to the pond to reduce the muck, but it all depends on your pocketbook - it isn't inexpensive, but if the goal is to have a pond to swim in, the less muck the better.

As for plants, look at American Pondweed, and the different types of Eelgrass. The nutrients are coming into the pond in the form of leaves, so having something to utilize the nutrients before they grow algae is your goal. Ponds with large underwater weed plant colonies typically have clear water.

If you want a more detailed aeration information, PM me your e-mail address.

My thoughts exactly, esshup.

Thanks very much for the detailed response! Do you mind some questions based upon it?

1) Don't you think the water jet I plan to install under the dock, aiming across the beach planned for the pond's northeastern shore, would alleviate the need for a summer diffuser in that lobe of the pond? That would get me down to two roiling water spots instead of three, anyway. (Viewing and swimming aesthetics and my wife's view of them, remember...)

2) Working on that same issue a bit, what would be the downside of using only one instead of two summer diffusers? Is it just that I wouldn't be aerating as much of the pond's area as is ideal, i.e. there would be some spot(s) where the substrate and water remain more or less as they are now (stratified in temperature and oxygen level, laying down muck)? That might be a trade-off I'd consider accepting, say, by putting a single diffuser in the pond's deepest hole as far out from its southern shore as I can while staying at the depth, leaving out a second one for its southeastern lobe (which I suspect is the obvious spot for a second one).

3) While we're at it, what's the reasoning for wanting to turn the water over at least once, preferably twice, every 24 hours? I know that it's a commonly accepted goal, but my education is lacking on why. I am a biologist, though, so don't be afraid to get technical on me if you're so inclined. :^/

4) What do you think of the idea of my placing one of the two winter diffusers close to shore by the pond's northwest "corner" (the sharp little point in the shoreline) and another one close to shore on the south side of the peninsula almost directly across the pond from that first spot, in the pond's southeastern lobe? Those are both spots where aquatic vegetation (a native pondweed in both cases, but I forget at the moment which species) other than Chara at least has a toehold, and I thought it would be good to encourage its growth.

5) You're obviously a Vertex fan, and I appreciate manufacturer/model recommendations as much as any other kind (so doubly thanks!). Can you tell me what you particularly like about their equipment, or dislike about what you see as their nearest competitors' equipment?

6) How deeply buried do you think the 1" poly should be running from the barn down to the pond's edge? It's very rocky around these parts - I'm told the pond was created using dynamite leftover from blasting out space for the house's foundation - so I may be in trouble if it has to be very deep. Winter temperature-wise I'm in USDA plant zone 5a (-20F to -15F), if that's important to the answer.

That's all I have for now, anyway. (Sorry about it being so much! :^/ ) I want to pick your and other folks' brains about aquatic plants to establish in the pond, too, but I'd rather leave that for another thread at another time.

Thanks again - and a lot!

Gerry

very good information. Thanks for taking the time to educate us all.

Thanks
David

Right, and as I see it, the mixture between the two caused by the horizontal movement of the latter might alleviate the need for a summer diffuser in that lobe of the pond. Or is there some fault in my reasoning that I'm missing?

As for the power of the water jet, the model I'm looking at (www.aquathruster.com) offers from 1/2 hp to 2 hp motors and can be equipped with an optional oscillator. (I haven't yet decided which size to go with or whether to add the oscillator.)


That's a great point. I think at present she's going by memories of aerators I didn't witness with her, or maybe just imagination. I've certainly never seen an aerator that I thought caused unattractive roiling, but she just might be especially finicky in this regard; if that's the case then I can hardly blame her, as I can be especially finicky about some things, myself. :^/ I'll spend some time with her checking out pictures/videos online to see if it might modify her thinking.

A question about the idea of an aeration system not being set up properly: How can one tell whether they're pushing too little or too much air through a diffuser? I know these things are adjustable (I mean, in addition to being subject to the cfm one's compressor is capable of producing), but I've not yet seen anything that tells one how to optimize the amount of air going through a given diffuser.

Rest assured, I share your concern about people/animals being able to get out of the pond if they fall in; in my case, with the entire pond being encircled by a walled bank, it's a concern even in the summer. (This summer my wife and I came home one afternoon to find that a neighbor's horses had found a breach in their fence and wandered into our woods quite some distance from their pasture. I hate to think what could have happened had they reached the pond, one or more of them somehow fallen in and we'd not come home anytime soon.) That's one of the reasons I'm so eager to put in the beach. I will definitely keep this issue in mind if/when I add winter aeration, too.

English springers, eh? Beautiful dogs! I'm currently searching for my next German shorthaired pointer pup, myself, so I've got bird dogs on my mind a lot lately.

I really can't thank you enough for going through all this with me, esshup. You're doing a lot to improve my education, and my pond will be better off as a result.

Gerry

Gerry
Have you posted pictures of your pond somewhere? I would be interested in seeing it.
Thanks
Dave

Here's a case study on what under aerating a pond will do:

http://www.vertexwaterfeatures.com/aeration/pond-aeration-and-lake-restoration-case-studies

Gerry:

Basically it's designing the system to utilize all the air from the compressor. The compressor is sized to meet the diffuser needs. All that is done is balance the "boil" between the diffusers via the ball valves. Diffusers in deeper water require more pressure than diffusers in shallow water. I have seen an extreme example of a diffuser in 12' of water not getting any air because of the shallower water diffuser using all the air - path of least resistance. That's why you balance it manually with a ball valve going to each diffuser assembly.

I have field bred ESS vs. Show bred ESS.

The field dogs have MUCH more white in them - easier to see, etc., etc.

There's certainly a cautionary tale being told there, esshup, but as a scientist I must say that it's difficult to discern exactly what it is. Too little information about the before situation, and too many parts moving all at once preceding the after situation. I'll think more on it, though.

That and your follow-up post about balancing the air output between the diffusers brought up a few more questions, if you don't mind:

1) How is it decided whether one should use a single or more diffusers at a single spot? I've commonly seen singles and doubles, and sometimes quadruples, offered with no explanation of when to choose which, and in a photo in that case study I can see where they even used a quintuple!

2) How does one balance the air output between diffusers when there is more air being produced by the compressor than all of the diffusers hooked up to it can properly handle? For example, say I use the same compressor for three diffusers during the summer and only one diffuser during the winter, or start out by trying only one diffuser during the summer with the idea that I can add more in subsequent years if doing so seems justified. How do I keep diffusers from being overwhelmed? Is the excess air simply bled off at the compressor somehow?

3) In such a scenario as I described above, where less than all of the air produced is being released through the diffusers, how does one know how to optimize the diffusers? Is measuring O2 at depth really necessary, or is there some way one can just eyeball the roil at the surface of the water, or what?

As always, your patient instruction is most appreciated! :^]

In GSPs it seems that rather than a clear-cut division between field and show breeding, there are breeders who aim mostly or entirely for field performance, and there are breeders who aim mostly for show performance but make sure their dogs still hunt. None of them seem to want their dogs to lose the abilities for which the breed was developed, thank goodness (though some of the field breeders will insist otherwise about show breeders). I've always preferred show quality with hunting ability because I appreciate an especially good-looking dog (I used to show but don't intend to anymore) and I'm just a foot hunter who isn't very competitive about it; I figure if I and the dog are having fun, that's all that matters. But I can understand other people feeling otherwise.

Dave, I tried to post a couple of pictures yesterday (good suggestion!) but my usual online photo host Photobucket wasn't working. Last night I finally realized that we can have a few photos hosted right here at Pond Boss. So I put these in the Image Gallery:







Zooming in on a section of wall lining the bank anywhere (if that's possible with these photos) you'll see it's made up of a heck of a lot of concrete cylinders that extend somewhat more than 2 ft above the water's surface. (About a third of the pond's wall is instead made up of stone from the pond's construction, but that's all on the shore nearest the house which is where the pictures are taken from, so you can't see it.) The fellow we bought the property from had a development/construction business, and we believe he used a variety of leftover materials (e.g. all those many concrete cylinders) from other jobs to construct his house and pond. There's even a large un-tiled space in the middle of the living room floor (made level by carpet scraps and covered by an area rug) where we think he ran out of leftover marble tile. :^D

In the sunset picture in the middle you can just make out a bit of a 2.4 ac natural pond not far beyond and about 15 ft below the 2.2 ac manmade pond I've been talking about, and then some of the several acres of marsh beyond that. We get a lot of ducks and geese! :^] Unfortunately, there's a lot of the invasive aquatic reed Phragmites growing around much of the natural pond and just starting to creep into the marsh; it's pretty but lousy for wildlife - and will really take over a landscape if left unchecked - so I'll be working hard at getting rid of all that starting this winter.

Gerry

Nice looking place Gerry, good luck with getting the aeration figured out and settled in. I am in a similar spot with looking at aeration so I am still reading and learning.
Dave

Thanks, Dave! Good luck with your pond, in turn.

I'm really glad I made my way here to Pond Boss in my quest for knowledgeable and experienced advice; esshup's been incredibly helpful right from the start (and hopefully he'll find time to indulge me with answers to my latest questions for him above, as well :^/ ), and I look forward to the day I know enough to pay his kindness forward, too.

Gerry