Pond Boss Forums AERATION Systems questions Fountain question

I am getting ready to have a fountain installed in my pond. Pond is one and a quarter acre and 22 ft deep. I want areation and my wife wants a fountain. I have been looking at floating pumps and I was wondering if instead of having the pump pumping from the top of the pond, would it be possible to extend the pickup for the pump down around 10 ft down with pvc pipe so maybe I can circulate that water column and get better aireation for the pond, has anybody tried this?? I know a fountain does not airiate the water very well because it’s just drawing water from about a foot down, but the wife gets what she wants and she really wants a fountain with lights and I was thinking I could have the best of two worlds going this route, any ideas? Or am I just pissing in the wind here, thanks
Gregg

Pulling it from 15 feet down would be even better.

I am not sure if pulling and pumping water from deeper depths will require more energy usage for the motor. Electricians or engineers may know that answer.

Your wife is right, fountains are nice and southing to watch. Lights make them more pretty at night. Keep in mind or aware and prepared that the fountain will be more time and money maintenance and more long term cost compared to a bottom bubbler system. As with most things bigger is more expensive. Expect maintenance cost/s after the first several years. Motors for fountains are overworked because they are lifting and throwing water upward into the air which is why they are appealing to your roommate. Pretty, pretty. Water has significantly more weight than when pumping air. 5 gal of water weighs 40lbs and 5 gallons of air weighs 0.86 ounces – 744 times less weight per 5 gallons. The higher you throw water the more energy it takes = motor stress. Lights also have issues. When the fountain system is running there are electrical hazard liabilities. Be sure to follow all precautions especially when people are near the operating fountain. Water and electricity do not play well together – be sure to keep your liability insurance up to date. One good option is to put the fountain on a timer when the visual effects are optimized and motor runs less per year lengthening the time between down times.

The deeper you pump from, the more energy it takes.
(signed) an Electrical Engineer

Thank you all for the replies. Just wondering how much protectin does a GFI really provide, I want this to be SAFE, SAFE, SAFE, because my wife and grandkids love to swim in the pond. Has anybody heard of someone being electrocuted from a fountain? I see at the lake of the ozarks most of the docks have electricity running to them wired through a GFI, I just don’t know if there is a short, how long before it trips. Has anybody heard of maybe an air fountain, kinda like what’s in a hot tub ?? Guess maybe I need to get on the phone and call some manufacturers, I just want to make sure nobody gets hurt. Bill, I was thinking of running LED lights that operate at really low voltage and current

1.) I agree with the advice to pull water from depth to provide some degree of aeration to the pond.

If you know the depth of your epilimnion (the top layer of oxygenated water) during the summer then I see two options. You could put your pipe intake a foot or two above that depth, and increase the oxygen content in the layer that the fish are using. Or you could make your pipe intake a foot or two deeper into the lower oxygen waters and perhaps expand your usable water depth to the fish. (I would probably go with the first option, and provide more oxygen in the layer the fish are using, to slightly minimize your risk of a summer fish kill.)

2.) I almost never disagree with Theo (he is an engineer and I am not), but I do not believe your pump is "lifting" water from depth. The rule of thumb requiring more energy to lift water means to lift it against gravity. For example a water well supplying 100 GPM with a producing water level of 300' below the surface will require much more energy than a 100 GPM flow with a producing water level of only 100' below the ground surface.

That is not the analogy to your pond fountain. Your 15' extension tube will fill exactly to the level of the surface of the pond, so you are NOT lifting any water to the intake of the fountain pump. Your only additional energy requirement should be the very small frictional pressure losses due to moving your fluid through 15' of pipe. I think a bigger problem might be changing the net buoyancy of a floating type fountain.

3.) I would be safe with a GFI in the wiring loop. However, I would be extra safe and have a pond rule that no one can wade or swim unless the fountain is turned off! 120V AC electricity and water do not mix.

A good point. I believe there would be some additional energy required to move the water through the additional length of pipe that has to extend farther down into the pond, but that would be fairly minimal. It's been either too long (or not long enough) since I took Physics.

Has anyone ever actually pulled water from down deep? That would be interesting to hear about.

"You can judge a man's intelligence by how much he agrees with you.
-W. E. B. Griffin

You can judge it even better when he picks the right times to disagree with you.

Discussion - Very good points and ideas so far.
For a 1.25 ac pond 22ft deep - How big of a fountain and the pumping gpm or gph are you thinking of buying??. If oxygenation benefit is an important factor, it is good to know the volume of water moved to get some sort of idea of how much aeration / oxygenation benefit the fountain will produce.

IMO it is important to remember at what depth in the pond the thermocline develops. Another important factor is what is the measured lowest and greatest water clarity during the summer Apr to November. If you want to increase the depth of the oxygenated layer the draw tube needs to be in or below the thermocline. Also the length of time the fountain runs will have a big influence on the oxygenation benefit.

For this particular application, how deep you place the intake suction hose will have no affect on the energy used. The additional drag of the pipe will lower the pressure of suction side however. It may modestly reduce the amount water that will be pumped (so it takes more energy per unit water pumped ... IOWs it would be a little less efficient). If the pump is above the water surface it will pull a vacuum (relative to ambient air pressure) at the pump suction inlet. The limit is the ambient head of air pressure which is ~33 ft. But say it is 2 ft above the pond's surface ... then the vacuum will be 2ft + the frictional pressure drop from the intake of the suction hose to the intake of the pump. IOWs the gravity below the pond's surface doesn't matter because the gradient exist there under static conditions. Gravity comes into play lifting the water above the ponds surface only.

The energy consumed is proportional to the product of mass flow and the (difference of the head pressure at the outlet and the suction pressure at the inlet). Generally speaking, pumps have very low mass flow rates compared to low head systems like paddlewheels and aeration. IOWs, for a given amount of energy, you can move much more water with aeration or a paddlewheel than you can with a pump. For the purpose of aeration, I do think that volume of the flow is very important. The fountain, for the energy used, will not contribute nearly as much to DO as aeration would. I would definitely try to negotiate with the Mrs. for the aeration.

So, my thoughts on most things that do "multiple jobs" are that they don't all the jobs optimally. Have you considered both bottom aeration and a fountain? I was in a similar dilemma, but with a much smaller pond. My wife wants aesthetics, I want happy water. Instead of possibly sub optimally aerating with a fountain, I decided to (eventually) get the separate tools to do both. I now currently have a bottom aerator that runs 1 hour over night to perform an estimated just under 1 complete turnover per night. My wife is slated to get a fountain in the near future so that we both achieve our goals. We will have a rule that no one is in the pond while the fountain is on, and will also be able to control when the fountain has power. The fountain being for aesthetics, I find it to be a waste of money being on if no one is out there enjoying it, so I want to be able to control when it runs.

Thank you all again for your replies and suggestions.
I have been researching for hours and contacting a couple of electricians about what I am trying accomplish. I will be calling manufacturers this week to see what the GPMs of their pumps are rated at, I have seen them from 40 - 140 gpms, those are 1 hp pumps, I am going to go with a 2 hp pump, can’t find any gpms rated with this size pump, so I have to make some calls.
I am going to do my research and buy everything this winter and install it this spring. It looks like nobody has tried this setup yet, so I am going to be the test pilot. I will be sure and keep everybody posted with the results,I know it’s not going to be as good as bottom diffusion, but hell if I can get more oxygen down to 15-20 ft that’s just that more water the fish can utilize, and momma gets her fountain ( that part is non negotiable lol) Just an fyi, when buying a GFIC, they came at human rated, trips at 4-6 milli amp, and at equipment rated, trips at anywhere from 10 - 100 milliamps. Keep this in mind when installing one, I believe your muscles will lock up at around 10 milliamps ( meaning you can’t swim) and it will stop your heart at around 30 milliamps, is this correct Theo? I am also going to ask the manufacturers about extending the intake down 15ft and see what they have to say about that.
Any and all suggestions you all make is greatly appreciated, thank you again, Gregg

I will check the notes from my last "Live Electrical Circuits" training (2023) tomorrow and see if that is mentioned.

Shock Effects from the world's largest aerospace company. They wish to remain nameless, so I will give them the code name of a Dr. Seuss character - Gerald McBoeing-Boeing.

Current Range and Reaction:
<1 mA - Generally not perceptible.
1 mA - Faint Tingle.
5 mA - Slight shock felt, not painful but disturbing. Most people can let go.
6-25 mA - (Women) Painful Shock, loss of muscular control. Range in which you can't let go occurs.
9-30 mA - (Men) Individual cannot let go but can be thrown away from circuit of extensor muscles are stimulated (by the shock itself)
50-150 mA - Extreme pain, respiratory arrest, severe muscular contractions. Death possible.
1,000-4,300 mA - Rhythmic pumping action of the heart ceases. Muscular contraction and nerve damage occur. Death likely.
10,000 mA - Cardiac arrest and severe burns occur. Death probable.
15,000 mA - Lowest overcurrent in which a 15A fuse or circuit breaker will open.

Use those GFIs around water!

I would just add that the energy-used answer somewhat depends on the pipe diameter employed to bring the water up 20ft. For a 2" SCH40 pipe there would be a 5.9psi (0.4 atm) pressure drop from bottom to surface at 200gpm, assuming a clean pipe. At 4" this drops to 0.2psi. Use a bigger pipe.

Again, thank you all for the replies.
I have been calling fountain aerator manufacturers today and got some useful information.
Scott aerator has a 2hp fountain aerator that puts out 110 gpm pump with an 8 inch intake, depending on which nozzle pattern installed. The intake tube extends about a 1.5 ft down from the bottom of the pump, just have to add a collar on that and put my pipe to the collar, that’s 15 ft of 8” pvc. He said they have never tried it, but in theory it should work, if not, just remove the pipe and run it the way it was manufactured, without the extension, it will aerate down around 6ft out of the box.
Then talked to Otterbine, their 2hp pumps will put out 210gpm, their intake pipe tapers from 6” to 8” (or vice versa) They also have one in their Gemini series that will put out 665gpm, but it only comes with one style nozzle pattern and I don’t care for the pattern of that nozzle.
Next was a Kasco, their inlet is the whole bottom of the fountain, no place to install an extension, if you could fabricate to the fountain, the pipe size would be about the size of a colvert and probably too heavy to keep the fountain floating, not to mention the bulkiness of handling it
Thanks
Gregg

Check the fountain mfg's to see what materials are used to build them. Otterbine uses stainless steel, I've seek Kasco with both aluminum and plastic impellers. Never saw a Scott unit.

All the pumps I have been looking at are stainless steel, just never thought about checking what material the impellers are made of, I don’t want a plastic one, especially at what the price of those puppies are.
So folks, do you all think this project is do-able, for the price I just want to make sure it’s worth it

If you use extension piping I would use thin wall lighter weight drain pipe not schedule 40. My concern is more about the motor quality and warranty and not the impeller material. Although sucking gunk including a dead fish up into the impeller could be a problem.

My testing has shown that most all ponds with even a little bit of wind action will normally and naturally mix down to 6 ft deep without a surface draw fountain. Your 1.25 ac pond if not tree sheltered and receiving good wind action could without a fountain naturally mix down to 7 maybe 8ft depending on wind exposure. Scott Aerator sales person saying "it will aerate down around 6ft out of the box" was a sales pitch or a naive representative.

Bill, do you think 210 gpm is sufficient flow for decent aeration? My thermocline, or I assume it’s thermocline, is around 6ft down, that’s while swimming the water gets a lot colder at that depth. The clarity in the summer is about 14”
Theo, thank you for clarifying what I thought on what milliamps it takes to have an effect on the human body, I hope everybody pays attention to that chart you posted. After seeing that, it WIILL have a gfic installed and nobody in the water while the fountain is on!!!
Retired on 40 that confirms what I thought on the psi, I don’t know where you got those numbers, I spent a couple hours trying to find exactly that info, thank you.
Jps, I don’t know what you do for a living, but wow, that info is very informative and detailed, that really helps me get a grasp on what I am trying to do
Drew, believe me, I know exactly how it is when the wife wants one thing and you want another, she wins. At least now she knows later on down the road if this setup doesn’t work out, bottom diffusion is on the list. Be sure and let her see Theos post on just what a very small amount of current will do to you…. Hope everybody else pays real close attention th that chart.
Essup, does that flow sound beneficial to you or am I just pissing in the wind here?
Gregg

Bill, do you think with the extension down 15 ft will get more DO at that depth. There is only about three trees on one end of the pond, I get plenty of wind action on the water, so much so that I just had the whole pond lined with 6 and 2 inch rock, wow, have you all priced rock lately. Ripples were eroding a shelf on my dam and I wanted to make sure if someone slipped in they would have something to grab on to get out, especially in the winter

I am not an aeration expert, but have read lots of excellent threads on the forum.

I think up-sizing the fountain for more aeration may be a losing battle because the bottom bubbler aeration systems are so much more efficient at adding oxygen to your water column.

Perhaps your best bang for the buck is to do a fountain designed mostly for the aesthetics to keep your wife happy, and add a bubbler aeration system to keep your fish happy.

FishinRod, I think that’s probably where I am heading, but in the meantime I still want to try this, just to see how it works. I have delved into this so deeply now, I am just curious to see what happens, hell I am retired and this little ( but expensive ) test will give something to do and might just be informative for the other members here, lord knows I get ALOT of good advice here, I just might be able to give back here, who knows, might just save somebody a little time and money…..

There's roughly 4,480,451 gallons of water in the pond. Typically with a bottom aeration system you want to bring a minimum of 1.2x the water volume to the surface every 24 hours to get it in contact with the air to transfer O2 to the water.

I don't think that a fountain @ 210 gpm by itself will be sufficient.

Sounds good to me. I am a strong believer in experimentation to solve complex problems, so I like your attitude!

I do not think the fluid flow will be much affected by your deep pipe, if you go with a large diameter.

However, it might mess up the buoyancy of your fountain a little. PVC pipe is only 39% more dense than fresh water. If you use heavier pipe, I still think you can easily add a pipe strap near the top with an underwater clorox jug to get back to the fountains design float level.

Good luck on your project!

P.S. Have your brought your wife in on the design phase? I have discovered that act scores me some additional points in the "good husband" column AND I don't have to revise things later since the project was approved at the highest level!

Don't use "foam core" PVC pipe. It will float in water. I went the cheap way some time back; and bought some to make crawfish habitat, then after it was made I realized that crawfish wouldn't use it if it was floating.............