I am moving forward with piecing together an aeration system for my share of 1.75 acre pond shared between 3 property owners, as well as exploring other solutions to improve our pond. I have attached an annotated satellite image to illustrate what I'm dealing with. I tried to get everyone to agree to a solar aeration setup where everyone could chip in then not have to worry about electric and various pumps, but ultimately I failed to convince everyone. The current agreement is each household takes care of their share of the pond.
My 0.6 acres is at the west end (far right) that I circled, and averages 3-4 feet in depth. Deeper holes in the pond are outlined with dashed lines. Historically, there has been a lot of plant growth and algae issues (we moved here in 2014). The pond is pretty old, and there is a good deal of muck everywhere. All depths were confirmed recently with a depth finder.
The asterisk (*) marks are existing diffusers from my middle neighbor.
The far east end is pretty shallow, mostly because it suffers from catching run-off that overflows from road (that is further to the SSW; out of the frame).
My understanding of pond aeration is that the more shallow you are, the more diffusers you need, thus my interest in getting a pump and couple diffusers installed. I'm hoping I can be set straight on a few items. Lets assume that cost is not much of a barrier at this point:
Pump location Will be housed inside my pole building. It is a dry space with concrete floor.
Pump For the area pictured, I have been looking at rotary vane, rocking piston, and linear pumps. I keep seeing linear pumps recommended for ponds up to 7' deep. Most discussions around here seem to focus on rocking piston and rotary vane. I see 1/4 HP rotary vane pumps paired with systems for "up to 2 acres" systems. Can someone set me straight on what the best choice would be? If we start getting control of the muck, we may gain an extra 1+ ft. of depth. Depending on where you read, I find conflicting information on the comparisons of linear vs. rotary vane vs. rocking piston. Sounds like linear pumps may be the quietest and most efficient for shallow water applications, but may need to have the diaphragm replaced more often. So I'm kind of at a loss of what to choose.
Tubing I'm still researching this, but my plan is a line that is buried (5/8" diameter) from barn to a manifold at the pond edge, then weighed air tubing from the manifold to the diffusers (5/8"). I'm not sure on distances yet.
Diffusers Still researching this as well. Open to suggestions as the number of options is overwhelming. I believe I would need at least 2 due to the shallow depth and irregular shape of my section.
I will be spending time searching the forum, but would appreciate any suggestions to get me started in the right direction.
Purchase a cheap wired indoor/outdoor thermometer. Go out in the pond in the deepest water, take temperature measurements every foot. If the temperature doesn't vary more than a degree or two, you don't need to add more aeration.
If you still want or need to put aeration in the pond, I would bury 1" poly tubing from the barn to the remote manifold at the edge of the pond. THEN transition to the 5/8" weighted airline.
During the winter I would shut off the one in 5' water depth and just keep the one in 4' water depth running. I would just look at rotary vane and rocking piston pumps. The rotary vane will be the easiest to do a rebuild on, and I am pretty sure you will get more air out of one vs. a rocking piston for the same electrical consumption.
The favorite diffusers around PB are the Vertex and Matala brands. They are mentioned more than the other styles anyhow. They are considered a membrane diffuser and require less maintenance than the stone or tube styles. You can install them and pretty much forget about them unless you are more ambitious, like me and a few others, and like to fiddle around the pond..then pulling them up once a year and cleaning the pond slime off the membrane would be recommended. I'm not sure this is really necessary and you risk breaking the plastic housing/fittings in the process. I bought my Vertex diffusers and weighted line form esshup (a post above) from his linked HoosierPondPros website.
After checking the temp difference between the bottom and top waters in the deep area, which would tell you if your pond is being turned over successfully, you still may choose to add aeration. If the small temp difference exists and additional aeration is not needed for turn-over, additional aeration could be added to aid in water surface conditioning on your end. This would help with any floating films that tend to develop in the lack of wind across the pond or during no-rain periods. These diffusers could be set much more shallow (2 to 3 feet from the surface) which will improve the surface turbulence, allow for more diffusers to be used with the same pump, and cover more water surface.
If you do NOT find that small temp difference, your pond needs more turnover and I would suggest putting at least one of your diffusers in the deepest water you have access to. This will aid in moving more of the deeper water to the top and, hence, the overall turnover of the pond.
Thank you for the information above! Your responses were timely as I just got information back from somewhat local company here on recommendations...and I'm not sure I liked those recommendations even BEFORE I checked back to this thread. They recommended a linear pump with tube style diffusers...neither of which are recommended by you. I tried doing more research on the pump (Stratus) and I find no company website. Did I miss it, or is this a "house brand"? Sounds like tube diffusers are a bad choice. I have 2 young boys and too many projects, so I don't need hardware that will need constant maintenance.
The company was touting how much less electricity the linear pump will use. I get that, but it is hard for me to even compare since I can't find the specs on the linear pump. I'm looking more into this, but I don't think I will plan to run it 24/7, so that electricity consumption issue gets blurrier.
I will buy the thermometer mentioned so I can take some measurements, but my end of the pond does end up with "floating films" (pollen, cottonwood fluff, other dust/dirt).
The largest two pumps they show (KLC100 and 120) would be candidates for using 3 or 4 diffusers at 4 foot deep (thereabouts). I know nothing of this brand, by the way. Should you want to go deeper with one or more of the diffusers (like 6 - 8 foot), you should consider reducing the number of diffusers. The max number of 4' deep diffusers would be 4 to 5 respectively. Otherwise, you start under driving the diffusers, not a big deal, but not optimal either.
3-4 diffusers will help with floaties, but the key word is "help". They will not eliminate normal floating films. Just an heads-up for expectation purposes. My diffusers will keep a 10 to 15 foot diameter of nice reflective water for each diffuser. The space between them still has floating films (or worse sometimes) especially during days without rain or wind.
When you check your pond water temps...start at the deepest part. Might as well take readings about every foot as you come up (you're already out there - might as well, the collected data might prove to be interesting) and see where the temp starts to change. You will find that the topmost 5 to 10 inches can be drastically different depending on time of day. For comparison purposes...compare the very bottom to 18 inches from the surface. Above that could be misleading. You are looking for a small (1 to 5 degree difference) from the very bottom compared to about 18" down from the surface.
Diffuser lines at 5/8" inner diameter will be best for your area of the pond and 3/4 to 1" inner diameter from the pump to the remote manifold. This size depends on how far the pump is from the pond/remote manifold. AND, you will want the 5/8" line that is in the water to be weighted so that is sinks. Most folks that have tried to sink the more affordable line options with creative ways have had a "fun-time" keeping it down, or more importantly bringing it up and putting it back down for maintenance/repairs, and ended up switching to weighted line in the long run (At least the few testimonials I have read here at PB). Get the weighted line.