Pond Boss Forums AERATION Systems questions Budget DIY System - Pick the idea apart please

I know it's difficult to give a solid recommendation without seeing the property, but I'd like to at least throw my idea for a DIY aeration system out there in case anyone sees any real issues with my plan.

The Pond:
We have a 20 year-old, 0.5ac BOW that's oval/egg-shaped, and was originally about 17' deep near the dam (the wider end of the egg-shape), sloping up to about 6-8' deep near the inlet (the narrower end). Given 20 years of silt I'm not sure of the current depths, though if my brother's ice fishing sonar rig is accurate, we probably have lost close to 2ft of depth due to siltation.

The pond is also about 700' from our tractor shed (the nearest power source), and we have a significant and pretty consistent slope from there down to the pond (it wouldn't surprise me if the drop were 20-25', though my brother and Dad are surveyors, so they could easily confirm).

My Planned System:
- A rebuilt 1/4 or 1/3 HP rocking piston pump (sourced from ebay; according to seller, it's rated at 3-4 CFM and up to 40 psi; pump to live inside tractor shed)
- Fitting to connect pump (1/4" outlet) to PVC pipe
- 1 check valve between PVC pipe and pump
- 700' of 3/4" PVC pipe to be airline from shed down to the pond
- 1 check valve between PVC pipe and splitter
- Airline splitter (preferably from 3/4" inlet split to 2 x 3/8" outlets)
- 2 ball valves
- 100' of 3/8" PVC airline, weighted with DIY concrete & wire weights (for diffuser in maybe 15' of water, near dam)
- 50' of 3/8" PVC airline, weighted with DIY concrete & wire weights (for diffuser in maybe 8-10' of depth, closer to inlet)
- 2 x 8" diffusers

So far, I've estimated this setup to cost $450-500.

Questions:
1. Any comments on the sizing of any of the components?
2. Do I need to bury the PVC airline, and if so, how deep?
3. Given the good slope down to the pond, do I need to do anything to prevent condensation?

I have no experience with aeration, so let me know of any thoughts, however trivial. Any ideas or comments would be appreciated.

Consider adding a pop-off relief valve at the pump in case something gets clogged or kinked. This way the pressure is released and your pump does not deadhead which could cause it to overheat.

Ball valves will work, but actual flow control valves will allow a finer tune, if needed, be more consistent/repeatable and not so touchy should you want to balance between the diffusers.

I am wondering why you are putting in check valves since your pump is up hill from the pond and no real chance of siphoning water to the pump? Does it have something to do with a piston pump? My system has a rotary vane pump.

Your sizing looks good, you might even be able to add a third diffuser. A pump curve would help determine this. Can you post the curve?

You do not have to bury the line for any reason that I can think of IF you can establish a constant down hill slope to the pond so that any condensation runs on out. Unless you might hit it with the lawn mower I would want to get it below the frost line at the pond so that pond water (when not in use) does not freeze in the lines and burst them.

EDIT: I'm not sure about the cost difference, but a lot of folks use the flexible underground line instead of PVC pipe. My pump house was about 40 feet from the pond so I put my valves in the pump house and ran separate pex lines into the water (underground) where I adapted to the sinking hose.

Condensation will be a problem.

I have not figured out how to beat it yet. I have the lines on grade all the way into the water and still had problems. We THINK the problems began at the manifold. Each night there will be a little condensation left in manifold where your valves are ,elbows, etc. Each night that remaining layer of condensation will freeze. The layers will build and build until the line closes. Apparently all the condensation "action" begins in the turns, reductions, etc in the manifold.

Our current plan of attack is this: Run my manifold for Summer aeration. In the fall disconnect the "Summer" manifold and hook up a single line that runs to a pack of diffusers. No idea if it will solve the issue or not.

Good luck!

I would put a check valve at each diffuser. Otherwise, the air line will fill with water to the water level of the pond when the pump is not running.

I forgot to mention adding a pressure gage at the pump. This will be helpful trouble shooting any future problems and can also help you determine the CFM by using the pressure reading and the pump curve.

Wow, already some great advice. Thanks!


Don't wonder too hard, because I have no idea what I'm doing... I just tried to read several others' threads about aeration and piece together some of their ideas, but I myself know basically nothing about plumbing, pipes, airlines, etc.


I'm looking at rebuilt pumps on ebay, so for most of the listings I'm not 100% sure of the model of the pump. If I dig up better info, I'll try to track down the pump curve.


You say that as a joke, but the way my Dad likes to mow half way up the mountain, there may be no safe mower-free zone haha.


I have to run 700' of airline, and those air hoses (even the cheap PVC ones) quickly get really expensive once you get larger than 3/8" diameter (with 1/4" fittings). Though admittedly, I think that 3/8" air hose would be much easier and quicker to install than the PVC pipe. My concern was durability on that cheap PVC hose and the air volume.

Is it likely that a 3/8" hose would be enough to run 700', and then push air down through about 25' combined depth of water to power 2 diffusers? Or would that most likely generate too much back pressure?


I had seen before that you were struggling with endless condensation issues. Since my pond is smaller and would probably be fine with just 2 diffusers, do you think using a Y-style fitting on my PVC pipe as the splitter might be better condensation-wise than a manifold? I'm just thinking maybe the softer angle and more volume inside might do better than having several tight 90-degree bends inside the manifold, though I suppose I'd still have a couple reductions after that Y where it could collect and freeze up.

I'll try to summarize all the advice here so far to make a revised plan (let me know if I missed something):

My Planned System - Version 2.0:
- A rebuilt 1/4 or 1/3 HP rocking piston pump (sourced from ebay; according to seller, it's rated at 3-4 CFM and up to 40 psi; pump to live inside tractor shed)
- Pressure gauge
- T with pressure relief/pop-off valve
- Fitting to connect pump (1/4" outlet) to PVC pipe
- 700' of 3/4" PVC pipe to be airline from shed down to the pond (not buried, for now)
- 3/4" PVC Wye (Y) fitting
- 2 x 3/4" to 3/8" reducer
- 2 flow control valves
- 100' of 3/8" PVC airline, weighted with DIY concrete & wire weights (for diffuser in maybe 15' of water, near dam)
- 50' of 3/8" PVC airline, weighted with DIY concrete & wire weights (for diffuser in maybe 8-10' of depth, closer to inlet)
- 2 x check valves right before diffusers
- 2 x 8" diffusers

For a 700' run, I would not use any main feed line smaller than 1" black poly....2" would be better! Small diameter line may SEEM cheaper, till you are replacing pumps every year or two due to excessive heat and head pressure from friction. Are you planning to use air stone diffusers? The need regular monthly cleaning, so nix the idea of anything other than self-weighted air tubing. Bury some Poly tubing below your frost line if at all possible, and install a buried valve box to balance diffuser stations. In all honesty, if you are not mechanically inclined, you will be far happier and maybe save money in the long run to get a professional system installed for you.....

Regarding buried vs not, pvc pipe, unless specially lined, will degrade in the sun. It needs to be protected from UV rays. Paint works, but doesn’t last long.

Very good point!

And...

Most pumps come with some sort of little filter for the intake air. The ones I have seen resemble a compressed air muffler made of sintered brass/bronze. While these little filters are adequate for short runs, I would advise stepping up to a pleated cartridge filter.

The filter I used was from McMaster Carr...part number 4369K31. I tested the amp draw with and without the filter and it was 0.1 to 0.2 amps higher with the filter in place. That seemed reasonable to me so I accepted it as "Good Enough".

Here's the link...

https://www.mcmaster.com/#catalog/124/422/=1drnv09

I chose this filter because it was the same pipe size that my pump offers at the connection. McMaster has higher CFM rated filters, but you have to bell up to 1/2" pipe size and that seemed unreasonable.

BTW, the filter comes with an element included so don't buy two replacement elements thinking you'll use one and set one back as a spare. I now have two spares.

Rex, in the near-term I'm only considering aeration if I can do it on a budget, given that I'm attempting to start a business thus need to be extra tight with spending. Someday if things turn a corner, I'd definitely consider getting a professional system put in, but in the meantime it's a question of cheap DIY aeration vs. no aeration (not cheap vs. expensive). Not trying to be arrogant, but I always seem to figure things out (more due to being bullheaded, methodical, and persistent than due to pure intelligence), so I get that in the long-term it might be better and cheaper to get the professional system, but I'd rather take one good swing at it DIY and get to sleep well at night knowing that I tried, learned, and grew, and that I didn't blow much of the precious capital I need to launch my business.

I appreciate your input. I haven't been able to find 1" black poly tubing even with a web search, but could up the PVC pipe to 1". That increases the cost a decent bit, but if it saves me from blowing pumps every little bit, I see how that would be worth it. I wonder though, wouldn't having a pressure release/blow-off valve between the pump and the airline save the pump from ever feeling the kind of back-pressure that could stress it? If that's right, I think there's still the issue of all the friction from having such a long run scrubbing off CFM by the time it gets down to the pond.

I'm planning to use 2 x 8" membrane diffusers so far. I'm thinking of putting them in a half bucket (top half sawed off) with a little concrete in the bottom to keep them a little off the bottom and a little bit protected from gunk coming in from the sides. I've seen several others on these forums who have used membrane diffusers and went for cheaper (not the self-weighted) tubing or even garden hoses, so can you explain why that's a concern? I guess I don't understand how the tubing being self-weighted makes it any easier to pull in the diffuser for cleaning.

Given your and others' suggestions, I'm seeing that burying the line is quite important, so I'll try to bury the line as much as possible and also the valve box.

Thanks Noel. I'll add that filter to my parts list...

Moneywise...have you checked in to having another electric service pole installed near your pond? Here in my east Texas county our electric co-op company charges only $2 a foot to put overhead electric in. You are going to be surprised how much you would use electricity at your pond if you had it. Just a thought. Good luck!! Welcome to the forum.

Drew, in case Rex doesn't jump back on soon, I'll try to explain what undersized pipe does to a pump...Ultimately the pump will have to work harder to get the air to the pond with smaller tubing. Try to blow through a coffee stir straw, then a soda straw. The small straw is much harder to blow through. The pump might be able to do it, but it can do it easier (more efficiently) with larger tubing. If the pipe is actually too small to carry the CFM you want then the relief valve pops open and the air would be released in the pump house and never make it to the pond. Some of the air would, but not the excess. The pump is saved, but the air is wasted.

Now take length into consideration. You can easily blow through a ring that fits you pinky finger (it's a very short pipe), now, go blow through a 100 foot long garden hose...it's noticeably harder.

"Sharkbite" is a brand of PEX pipe (lowes) and can easily be used to run your air lines underground. It is more expensive, but really easy to install. NOTE: PEX line also takes special tools to "do it right" for the fittings.

I did not used DIY weighted line. I used the stuff made to sink and it works real nice. I can imagine how DIY line with "stuff" strapped to it could be cumbersome to use especially when moving and/or cleaning the diffusers. I moved mine at least twice to get them just the way I wanted them and I pull them up in the late summer for cleaning. I'm not trying to talk you out of using whatever because you can really save some money upfront using Dollar store garden hoses and "stuff" for weight. You will just spend more time installing and messing with it. The weighted hose I bought (from Hoosier Pond Pros - www.hoosierpondpros.com/ - essup here on the forums) did not even try to kink during my install. I have duck decoys tied to my diffusers and use a little boat to pull them up for cleaning. It is not as easy as it sounds especially by yourself, or with a dingbat friend who can't row a boat...comical - not easy. LOL "Stuff" hanging off the line would just make it more difficult and I can not imagine what bricks or cinder blocks would do to the installation efforts, do you have diving gear?

Since you're a mathematician maybe you dabbled in physics a long time ago...

...you might recall that resistance to laminar incompressible fluid flow through a tube is inversely proportional to the radius to the fourth power. Air is compressible and there's a whole field of engineering dedicated to computing its flow, but the relationship remains exponential.

3/4" ID for 700 ft would work for the rocking piston pump that produces higher pressures of 50-100psi. Lower pressure pumps for sure require the 1"ID.
https://www.tractorsupply.com/tsc/product/100-psi-polyethylene-flexible-coil-pipe-1-in-x-300-ft
As Flame noted - Be sure to check with your local electric company about installing an above ground 'pole' line to the pond with & without a meter base.