Pond Boss Forums AERATION Systems questions Roll-your-own aeration system (pics)

Hi all,

Long-time lurker, first-time poster.

I have a .7 Acre pond (old quarry) with an average depth of 5 feet that was drained and graded about 5 years ago. No natural inflow or outflow other than runoff and seepage when the water gets high. The field to the right in the first pic is uphill and there is a berm with trees on it to aid in keeping the soybean/corn field runoff from entering the pond.




(Photos taken Fall 2008)

Previous owner had used a Kasco circulator to help stir the pond. I used it the first year I owned the place and it cost me ~ $70 a month to operate 24/7 with not much noticable effect. Didn't do anything last year for lack of time and the pond got "gross".

Pond was stocked with FHM which still seem to be hanging in there. No other fish that I know of.

Let me state for the record that I contacted Ted at Forever Green and he gave some sage advice. Didn't end up buying a system from him (more in a minute) but I did buy Bottom Line from him (Thanks Ted!)

My passion and hobby is aviation (not fish or ponds yet) and am building an airplane - so I just couldn't help myself when it came time to do an aeration system. I'm a "homebuilder" at heart.

So after entirely too many hours on this site, another koi pond site and a million supplier websites, I decided on a roll-your-own aeration device supplied by a linear air pump.

Purchased a Medo LA-120 for ~$400 because it was widely reported to be "under spec'd", had no diaphragms to be replaced and had many reports of zero service needs for 5+ years running 24/7. Best of all it pulls about 120 watts while delivering 4.2cfm (per manufacturers specs) at 5' of water. (all numbers based on spec sheets not personal measurement - except power. It pulls 150 watts with no backpressure at all and about 120 watts in my pond. I stalled it briefly by plugging the supply and the power dropped to a mere 40 watts.)

Supply line is Ted's Bottom Line.

Now the roll-your-own aspect. I toyed with two 2-disc stations but decided to experiment with a Wisconsin knock-off of a popular 5-disc station model. Why - because bigger is better and I wanted to see how it would perform...


Thus:


I acquired the 9" discs from an online supplier for ~$15 ($18.50 with S&H) each. Claim they are "fine bubble" setup - have no way to verify that. They are 3/4" threaded molds for the frame.

Decided to center-feed the system and branch in a "TEE" format since the local home supply doesn't make a fitting to do a 6 way 3/4" PVC split.



The outboard pipes (vertical in the above picture) are not part of the air system. I just cut fish-mouths (see - I'm taking my aviation knowledge and crossing it over to fish!) into two additional pieces of PVC. These are solvent welded to the surface of the pipes and then I added zip ties for added joint strength.


I angled the barb fitting so that the supply line would clear the outrigger support.


Lastly, I took a 12"x12" cement paver, drilled some holes in it with a masonry bit and zip-tied the whole contraption to it (sorry - was in too big of a hurry to test it and forgot to take pics at that stage.) A piece of line around the base and another zip-tie connecting the supply hose to the rope (strain relief for the barb fitting) and it was ready to test.


I haven't done any photos or video of the gizmo in action but it seems to move the water - and boy does it raise a stink when it is running (yes - I've been following the double-every-day startup routine).

I can see very distinct cross-shaped outflow pattern coming from the center of the "boil". Took the canoe out and held my breath. Seems to be "welling up" pretty significantly in the center and the bubbles are still small (I'd guess 1/16" - 1/8" at the surface).

Any guesses as to the turnover rate I should expect to get with this contraption? May end up breaking this beast down into two (or maybe even three - I have a spare disc) separate stations, but thought I'd give this a whirl for a while.

Other than show & tell - I did have a question. How will I be able to tell whether one central lift station is working vice several distributed and would it matter on this size of a pond?

One last plug - Ted is the man. No - I don't work for him (but I am from OH originally! ) but do sincerely appreciate that he answered my questions.

Barry

What, no safety wire? Welcome to the forum Barry, glad to see another aviation buff on here and not far from Oshkosh.

Nice looking pond and very interesting aeration set-up you've built, I too have a small linear pump for my pond but using a soaker hose for aeration in shallow water.
What species of fish do you hope to stock in the future?
I think your system would be ok for that size pond but you should get more info from people with lots of aeration knowlege soon.

P.S. What type aircraft are you building?

Actually - VERY close to OSH. I work for EAA...!

I'm building a Sonex 2 place aluminum tri-gear. It is a club project for employees. But this is a Pond forum so back to the topic at hand.

I will probably go to the appropriate sub-forum to discuss goals, fish and weeds - but briefly I want to clean up the pond to make it a decent swimming hole for my three fry (6, 4, 1 - years not inches ) and then possibly stock with something that the kids would enjoy catching themselves. Low maintenance fish stock since I have more than enough to do just to keep the kids mowed, the grass out of trouble and build a plane...

I'll take some pics & video of my setup in action tonight.

BTW - the PVC parts for the project were less than $10 and the gadget probably took less than 3 hours including lots of "What are you doing Daddy?" questions.

Where did you buy your diffusers??? I haven't found any that reasonably priced yet. The rest of it looks fine to me, I have the same thing in mind for my pond, it needs it sooner rather than later.

PM Bill Cody - he is very modest and does not advertise, but he is an excellent source for DIY aeration systems.
He has been been very helpful to me as well as others.

Check your PM

Took some video tonight with the little hand-held Vado HD.

First one is from the shore. The digital zoom is on since this camera has a really wide-angle lens and the float seemed very small. Watched a few other videos on YouTube and the "boil" that others get is much larger - but I still think I get a very strong outflow current (video of that later).




Jumped in the canoe and headed over. Against my better judgement I stood up in the canoe to get above the upwelling. (SWMBO would kill me if I dunked her camera) Probably 10' away and camera is 5' above water.



Same setup as before but almost directly overhead...



Lastly, I tried to capture the effect of the outflow current.

Setup for this - aim canoe straight at upwelling with a couple of easy paddles (half walk speed or less). Watch the underwater weeds as I approach (may need HD to see them well). They are being "blown" by the water current. Then as I enter the bubble zone I aim the camera at the bubbles and hold it steady. I'm not zooming out - that is the current from the outflow pushing the canoe backwards. It stopped my forward progress(drift) and pushed me sideways.



I guess in the end, the proof will be in the results. Stink coming out of the foam is less tonight, so it would seem that it is starting to improve in that regard.

On the 2 hour run tonight.

For the curious, I took some close-up pics of the "Brand X" diffuser discs that I'm using.



and with a ruler



I am NOT going to count all of the holes - but

4 rows per CM
6 holes per centimeter (looks like hole and space is roughly equal so holes are about 0.5 CM each or 500 microns.)

So . . . 24 holes per CM^2 and a 9" disc is about 346 cm^2 - yields 8300 holes. Subtract 10% (my W.A.G.) for dead space between the sectors yields 7500 holes in a 9" disc.

I didn't ask any of this before I bought - just went with "fine bubbles" but had a question in a PM, so I thought I would share.

I'm speechless - that was too cool - thanks for sharing this. Do you mind sharing your overall cost of development? Any clues if you'll be using less electricity?

Outstanding work. I'm thinking Aquatic Ecosystem 9" diffusers. Very good and reasonably priced. I made a home brew co-active station using 2 of them in 3/4 acre and 12 ft deepest.
You have PLENTY of turnover of water.

*ack* patoo, METRIC! Just when I get comfortable converting fractions to .000's of an inch, someone goes and uses the wrong side of the ruler!!

esshup, check your mail!!!

Regarding electricity usage:

I went back and looked at the meter reading from the barn meter in Sept 2008. I paid $73.11. Other than some overhead Mercury Vapor lights, there is nothing in the barn that consumes electricity in the summer. I'm pretty sure that I didn't leave any lights on for extended periods of time. ergo - the Kasco used most of that juice. I'm not positive but I think it is a 3/4 HP pump which in theory should pull 560 watts. If I ran it 24/7 for the month of August (I did) I should have pulled 416 KWH at $0.115 comes out to $48. So maybe I did leave a light on...

We'll go with $48 to run the circulator.

The new pump is on the house current for now but I have one of those plug-in energy devices (Kill-a-watt) which accurately measures "real" power (as well as apparent power) and are the figures I quoted before.



OK - back to the original question... Assume (and that is a big "ASS" out of "U" and "ME") my new setup is as or more efficient than the old circulator at moving water, I would expect my electricty cost to be ~$10 a month or a 79% savings on electricity. (Before everyone gets all excited - remember my pond is only 5' deep. This would change dramatically if my pond was just 8' deep - I'm using a linear air pump which does not like working at high PSI.)

The pump cost me $411 including shipping.

The diffusers cost me $112 including shipping and I have a spare disc, so call it $93

The hose cost me $129 from Ted at Forever Green (right from the website.)

The plumbing cost me ~$20 (elbows and tees were around $0.60 a piece and I think 10' of Sched40 was ~$3 which was the original $10 that I quoted. But I needed a couple of unions and barb fittings for the 3/4" poly that is coming up.)

I had the cleaner, glue and zip strips.

To cut the fish-mouths on the support pipes, I bored a 1 1/8" hole about 4" deep into a 2x4. Then drilled at 90 degrees to that bore with the same bit. Slide pipe in and drill down. Could have done it on my drill press - but in 2 years, I haven't managed to unpack my shop tools... (LOW MAINTENANCE FISH!!!)

No enclosure needed as I will put the pump in the barn furnace room.

I bought 200' of poly 3/4" pipe to get the air from the barn to the pond (probably only 150' needed) at $24.

My time - well, I hate to put a dollar figure on my time. If I did, I should spend more time at work...

So $411 + $93 + $129 + $20 + $24 = $677

No enclosure, no pressure gage or manifold, no valves (switching or check).

One of the vendors WHO SUPPORT THIS BOARD (and should be patronized whenever possible!) could have probably set me up with a nice system for ~$1000 (maybe even less).

For me, I got to have fun, save a "small" amount of material cost and hopefully get a pump that will save me significant $$$ on maintenance and operation costs over the course of the next 5 years. (say $2K in electricity and $200 in pump rebuild/maintenance).

Or I could be full of it and find out that I wasted $677 on a lark. That is what "homebuilding" is all about!!!

only went there because I had seen some mentions of slit and bubble size in microns by some of the manufacturers.

Will gladly flip the ruler over...


I think that works out to 132 slits per square inch...

Where did you buy your diffusers?

ElksinWi, Thanks. I was just giving you a hard time. 0.393700787 works pretty well for converting CM to Inches.

I've worked so long reading prints (they ain't blue anymore) and converting .000" to fractions that I ended up buying a tape measure that was marked off in tenths. I slow down in converting when it gets to odd 16ths of an inch. Then I have to break out the calculator.

I didn't know they even made measurements that small!

2.54 baby. use it every day that I work on a foreign ship.

Can a Mod let me know if it is OK to post in the thread where I got the diffusers? I don't want to offend any supporters of this site (which don't think the supplier I used is).

I've PM'd the two folks who asked for the moment.

What is that?? A currency exchange rate or something??

1 inche = 2.54 centimeters

I'm with ya!

I have a question. What size Medo should i go with for a pond no more than a 1/4 acre about 6' deep? Looks like the 120 may be too large. I am thinking in line of an 100 or an 80 and using no more than 2 9" discs . Hope I am not hijacking your post. Thanks.

ElksinWI;
Good job on the system. I would think the boil you're producing is more than adequate aeration for your .7 acre pond. I have a windmill system that won't compete with your boil, and it aerates my .75 acre pond just fine with one stone on.

Take care;

Joe