DIY POND VAC

[Event Horizon]

I currently use a shop vac to do my spring clean of the pond. It works, but it could be better. What I don’t like is that if you don’t pull the vac hose out before it fills up, the ball will kick in and stop suction and any water / muck in the hose will rush out back into the pond. If this happens you instantly loose visibility, and it is more difficult to clean. I want to make a vacuum that will run continuous so this won’t happen.

Basically what I want to make is an inline system, and here is my thinking.

I have a 1200 gph pump I am not using that I think could work for this. I start with a barrel with a screw on lid maybe 10 or 15 gallon. I would drill two holes in the barrel, a input & output. The intake would come through the side and a size I could connect my vac hose to in order to vacuum. The output would connect to the pump, up and out, where it would connect to a length of hose to drain into the garden. I could avoid the debris hitting the open intake of the pump by adding separate layers of grates until it reached a small size where it could be sucked up and dumped into the garden.

The input/output and power line would have to be glued tight so unit won’t loose pressure. I figure if the barrel does not leak the water should pass right through.
I would bring this out and connect the vac hose and the exit hose. I would then bring out a garden hose and fill the barrel through the exit hose (to prime it). At that point I should be able to put the vac end in the pond and the exit hose in the garden and start it up.

Anyone see any major flaws with this idea? I realize leaves would clog this up, but between the skimmer and my pool net, my issue is smaller material.

 

[Waterbug]

Built the exact same thing about 15 years ago. Back then there were several people in a pond forum, Gardenweb I think, creating vaccuums.

The container I used was a 3.5 bucket with a screw on lid. I even sold a couple before It became clear there had to be better options. The issues were:

1. Getting a perfect seal isn't possible. Possible on a metal tank built specifically for the task, but these plastic things just move too much. The solution, which did work, was to place the entire tank into the pond. Instead of sucking air into the tank it just sucked in water. With even a small air leak the tank loses prime pretty fast.

Smaller tanks are less likely to collapse, pressure is lower inside the tank so they can collapse. Back in the day some friends used larger tanks, little bit different configuration, and they collapsed in an impressive manner. One guy screwed or bolted wood stays on the tank's outside and that did stop the collapsing. I Googled to see if his rig was still around and it is, Floyd's Pond Vacuum. Those were fun days to be sure.

2. Forget about the mesh, grate deals inside the tank. Looks better on paper. String algae and leaves are a problem. Trying to catch it inside the tank might buy you a little extra time but a clog is still the result whether it's the grate or the pump. It's a way bigger problem than it seems. The fine stuff can go right thru the pump so for sure fine mesh isn't needed and would clog. The solution was to use a venturi type vacuum first to remove all the big stuff first. Let the water settle for a day or so and then use a suction vac like you have pictured.

Pulling this huge mess out of the pond, taking it apart to clean and putting it all back was a pain.

After maybe a dozen designs I ended up with the Silt Vac. Basically just a more simplified version of the pump in the bucket. Using PVC pipe instead of a tank eliminated collapse risk. Making it all smaller made use easier. The leaf trap was easy to clean, but still a pain unless big stuff was removed first. I've cleaned a few ponds in my day, the grate/tank type deal would have to be cleaned out maybe 50 times for a good size pond. With a venturi that might be only 5-10 bags worth which is way easier and you're not losing water so it's much more relaxing.

Another good vac for this type of cleaning is Gene's DIY Super Pond Vac. It solves the losing prime by using components designed to be air tight, but they do cost. This rig is basically the exact same setup swimming pools have except Gene's is portable. New ponds can build this type of thing right in the pond just like a swimming pool. But again, trying to remove big stuff using this would require cleaning the priming pot many, many times. Not reasonable.

One last thing I learned serendipitously was using the the venturi type vac on a regular basis kept the pond very clean. There wasn't the build up of silt. So I was down to using the Silt Vac maybe once a year, but even then, not much to remove. Big stuff is where silt comes from.

 

[DrCase]

I use my shop vac , Works good but I don't like the dumping
When I get done with the pond I'm still working on I need to make something better also

 

[Catfishnut]

At work we have a "cleanup drum". It is a 55 gallon metal drum with a heavy metal lid which just sits on top. The lid has a rubber gasket to seal it, but it does not clamp, screw or bolt on, it just sits on. Vacuum pulls it tight to seal it. The vacuum is generated via an industrial air mover, which is nothing more than a vortex venturi. The venturi or vortex unit is about 4-5 inches in diamter and 12 inches long. You hook it up to your air compressor and the venturi effect pulls a vacuum inside the drum. The hose is just a vacuum cleaner type hose, maybe a little beefier. At the bottom of the tank there is a spigot drain. The entire assembly sits on a wheeled cart so you can roll it around with ease. It wouldn't suck up rocks, but it will suck up sand and gravel and fish if you're not careful.

The concept is quite novel. No moving parts, no filtration items, no priming, no electricity. But, you do need a powerful air compressor with a large volume tank.

Not sure if that is useful to anyone, but I thought you could entertain the idea and come up with a design that suits your purposes with some of the information.

Catfishnut

 

[Event Horizon]

Thanks for the advice guys.

No air compressor yet Catfishnut. :sad:

I had noticed there were many designs out there, and that my idea had likely been tried.

I have a different smaller drum as you suggested that might hold a seal a bit better than a screw lid. The shape of this barrel should help with the collapsing and I think I could make a rubber gasket with a bit of rubber liner which might help the seal. I could scale this down and use it as a sludge remover. With that said they do say the definition of insanity is trying the same thing over and over expecting a different result.

Looks like this spring I will stay with my shop vac. I will do some reading on what you sent me Waterbug and decide what to make over the summer. Im thinking your Muck Mop and Silt Vac will be the way to go.

 

[Waterbug]

Back when a bunch of us were screwing around with vacuums, before Floyd's, either Floyd or Mr Bill had a setup like Floyd's without the stays on the side. It was a metal drum, can't remember if it was a standard 55 gal drum. But it was a pretty serious big metal drum. He collapsed that thing like soda can just using a shop vac I think. He posted a picture, wish I'd saved it. Picture is worth a 1000 words.

Going back to clogging, the filters inside and needing to vacuum out big stuff first...I remembered today that the biggest clogging issue for the Silt Vac isn't the pump or leaf trap, it's the vac head. A big wad of leaves or string algae and you're done. With leaves you can move the head slower to reduce clogs, but then you're pumping out more water so it just wasn't a good deal.

As far as I know I'm the only one who ever created the exact same design you have pictured. If you have the time, parts and inclination I'd say build it. The parts aren't expensive and it's an easy build. Maybe it works good enough for you and your pond. For sure you'd learn a lot and maybe figure out an even better vac. Inventing stuff requires you start some place. If you really just want a clean pond I'd say stick with one of the designs I gave links to. When I was done I had a pile of discarded designs the size of 3 SUVs...I kid you not.

 

[Event Horizon]

Considering I have a spare pump and other parts, you are correct in that this will be a cheap build for me

The issues seem to be drum collapsing, getting a good seal, clogging, and excessive water loss from the pond.

Drum collapsing: I am going to make the unit from ¾ plywood and waterproof it with a marine type paint.

A good seal: The box and lid will be tongue and groove with some sort of rubber to act as a gasket. I will double up on the plywood for the lid and use some sort of snap buckle to keep the lid on. I will find something more industrial that the attached picture, and use 6 to 8 of them.

Clogging & water loss: If the output had a Y connecter, one end would go to the garden and the other end would return back to the box. This would do a few things. First off I could regulate the output of water from the pond to the garden by returning more water back to the box without restricting the pump. Doing this would help to keep debris mixing in the box, not just one way onto the screen. This would also allow me to put 100% of the water into the box to really stir it up if it starts to clog and slow.

I started thinking that having a plate in the box might help as the debris would hit this slow down, not just go straight to the grate. It would also have the water move different if I were to run 100% of the water back into the box to mix things up.

I agree with you that if there is a lot of string algae nothing is going to work. So far my pond has not had any on the bottom, only in a few shallow areas and the water falls. If this works it will be nice as I will be able to vac the bottom without spitting out 1,000 gph into my garden. I will be able to set the Y valve to suck up the silt, if I were to hit a few leaves and it started to clog at the vacuum head end, I could just open it up full and increase the suction.This could also end up being a piece of garbage to add to the pile. I have a table saw, lots of plywood, and the pump. For a bit more hardware and the excuse to build something, I might just give it a try this summer.

 

[Waterbug]

I like the plywood idea. Never thought of that. Since these vacs are only used once in a while it should hold up fine. And besides, these things always need revisions so building prototypes as cheap and fast as possible to learn faster is a good idea imo.

You'll only want a rubber gasket on one side. In the lid's dado would be my preference to keep it protected. Two gaskets only provide more opportunity for leaks, the extra surface between the 2 gaskets.

You're right about the clogging...it all depends on what is vacuumed. String algae will screw anything. And even leaves act differently depending on the type and how decomposed. You just never know. In my case I needed vacuums that would handle any case.

The Y to try and keep the grate from clogging is interesting and worth a try, but I'm not hopeful. I have seen similar type ideas on filters. The most successful would probably be the rotating drum filters. If you haven't seen these it is worth a check, might give you some ideas. And in very high end industrial filters the concept of automatically washing grates is used including long rotating mats. Also a good source of ideas. Learn from their hard work I say.

The reason I'm not hopeful is just the mechanics of water pressure. The pump creates a lower pressure which is why water comes thru the grate. Pushing water back up thru the grate would keep that small spot clear, but would not allow any water to flow down thru the grate in that open spot because water is being forced thru that spot in the opposite direction. I expect where ever water can flow down thru the grate will clog and the Y will keep a visibly clear spot but water will still not be able to pass so the grate effectively would be clogged, stopping water getting to the pump which cuts off flow thru the Y which would then allow water to go down thru the open spot and it to would clog.

I understand your thinking that the Y would keep the debris stirred up so it wouldn't "settle" on the grate. Unfortunately that's only wishful thinking. Water pressure in the upper chamber is higher than the lower, again, why water flows thru the grate. So any debris getting close to the grate will have a higher pressure above it pushing down. It glues it in place. Remember you already have a lot of turbulence from the incoming pipe. You could for example move the incoming pipe down, parallel with the grate, so the incoming water flowed across the grate to keep it "clean". But that fails too for the same reason, different water pressures.

What people have tried to do is make that Y flow move around the grate, The rotating drum moved the grate instead of the water jet. Moving the grate out of the water and washing it always seems to be a key feature, but that doesn't help you.

So maybe a rotating drum instead the tank. I personally wouldn't bother, just tossing ideas around.

One of the things I did, and you can see it in the Silt Vac's leaf trap, is make the grate surround the pump. Basically the grate would be the shape of the inside but 1-2" smaller.

I like Fig B best because as the grate clogs it expands and presses against the sides and bottom. So the sides can stop it from breaking. And it's easier to build a floor to stop it there too. Fig A, once clogged, will be just like the tank and collapse.

It's worth pointing out the small amount of space in Fig A for debris to collect. There is a Catch-22 with these things. Fig B looks like it could hold a lot of debris, but it doesn't hold any more the Fig A because these only hold as much as will clog the grate.

It does take a certain thickness of material to actually clog water flow since water will flow thru debris to some degree. I make the grate have as much surface area as possible rather than total volume. Firstly because if it takes 2" of a debris to clog water flow if I have 5 times more surface area I can catch 5 times more debris before clogging. For example, say the area inside the tank above the pump was 1'x'1'x1. If I only lay a grate across the bottom, like in your picture, I'd have a 1 sq ft grate. But in Fig B I'd have almost that same bottom grate plus 4 sides for a total of almost 5 sq ft.

There is another benefit to more sq ft. It spreads out the amount of watering flowing thru the grate at any one point which reduces the water pressure at that point. This reduces the compaction of the debris which allows a thicker layer of debris while still allowing water thru. So that's another maybe 25-50% more debris to be collected.

I used this same principle to collect extremely fine suspended particles in a fabric filter. The particles collect on the fabric but still allow water to flow thru very slowly so that the particles themselves became the primary filter media trapping smaller and smaller particles. That's exactly how a diatomaceous earth pool filter works. The trick is reducing water flow to almost zero and that's done by making a huge (long and skinny) filter.

 

[Waterbug]

Since the tank will be above the pond you'll get some back flow into the pond when the pump is turned off. If you lift the vac head out of the pond before turning off the pump then no problem.

I don't know of any check valve that could handle leaves, string algae, etc., so I don't think that would be an option.

If the outflow ends up being down hill, below the pond level, water would continue to flow after the pump is turned off unless the vac head is lifted out of the pond.

 

[divedaddy03]

I like the plywood idea. Never thought of that. Since these vacs are only used once in a while it should hold up fine. And besides, these things always need revisions so building prototypes as cheap and fast as possible to learn faster is a good idea imo.

You'll only want a rubber gasket on one side. In the lid's dado would be my preference to keep it protected. Two gaskets only provide more opportunity for leaks, the extra surface between the 2 gaskets.

You're right about the clogging...it all depends on what is vacuumed. String algae will screw anything. And even leaves act differently depending on the type and how decomposed. You just never know. In my case I needed vacuums that would handle any case.

The Y to try and keep the grate from clogging is interesting and worth a try, but I'm not hopeful. I have seen similar type ideas on filters. The most successful would probably be the rotating drum filters. If you haven't seen these it is worth a check, might give you some ideas. And in very high end industrial filters the concept of automatically washing grates is used including long rotating mats. Also a good source of ideas. Learn from their hard work I say.

The reason I'm not hopeful is just the mechanics of water pressure. The pump creates a lower pressure which is why water comes thru the grate. Pushing water back up thru the grate would keep that small spot clear, but would not allow any water to flow down thru the grate in that open spot because water is being forced thru that spot in the opposite direction. I expect where ever water can flow down thru the grate will clog and the Y will keep a visibly clear spot but water will still not be able to pass so the grate effectively would be clogged, stopping water getting to the pump which cuts off flow thru the Y which would then allow water to go down thru the open spot and it to would clog.

I understand your thinking that the Y would keep the debris stirred up so it wouldn't "settle" on the grate. Unfortunately that's only wishful thinking. Water pressure in the upper chamber is higher than the lower, again, why water flows thru the grate. So any debris getting close to the grate will have a higher pressure above it pushing down. It glues it in place. Remember you already have a lot of turbulence from the incoming pipe. You could for example move the incoming pipe down, parallel with the grate, so the incoming water flowed across the grate to keep it "clean". But that fails too for the same reason, different water pressures.

What people have tried to do is make that Y flow move around the grate, The rotating drum moved the grate instead of the water jet. Moving the grate out of the water and washing it always seems to be a key feature, but that doesn't help you.

So maybe a rotating drum instead the tank. I personally wouldn't bother, just tossing ideas around.

One of the things I did, and you can see it in the Silt Vac's leaf trap, is make the grate surround the pump. Basically the grate would be the shape of the inside but 1-2" smaller.

I like Fig B best because as the grate clogs it expands and presses against the sides and bottom. So the sides can stop it from breaking. And it's easier to build a floor to stop it there too. Fig A, once clogged, will be just like the tank and collapse.

It's worth pointing out the small amount of space in Fig A for debris to collect. There is a Catch-22 with these things. Fig B looks like it could hold a lot of debris, but it doesn't hold any more the Fig A because these only hold as much as will clog the grate.

It does take a certain thickness of material to actually clog water flow since water will flow thru debris to some degree. I make the grate have as much surface area as possible rather than total volume. Firstly because if it takes 2" of a debris to clog water flow if I have 5 times more surface area I can catch 5 times more debris before clogging. For example, say the area inside the tank above the pump was 1'x'1'x1. If I only lay a grate across the bottom, like in your picture, I'd have a 1 sq ft grate. But in Fig B I'd have almost that same bottom grate plus 4 sides for a total of almost 5 sq ft.

There is another benefit to more sq ft. It spreads out the amount of watering flowing thru the grate at any one point which reduces the water pressure at that point. This reduces the compaction of the debris which allows a thicker layer of debris while still allowing water thru. So that's another maybe 25-50% more debris to be collected.

I used this same principle to collect extremely fine suspended particles in a fabric filter. The particles collect on the fabric but still allow water to flow thru very slowly so that the particles themselves became the primary filter media trapping smaller and smaller particles. That's exactly how a diatomaceous earth pool filter works. The trick is reducing water flow to almost zero and that's done by making a huge (long and skinny) filter.

I really like what you are doing, please keep me/us updated on your progress! Waterbug is very knowledgeable in this stuff and I'd take his advice to heart.

 

[divedaddy03]

At work we have a "cleanup drum". It is a 55 gallon metal drum with a heavy metal lid which just sits on top. The lid has a rubber gasket to seal it, but it does not clamp, screw or bolt on, it just sits on. Vacuum pulls it tight to seal it. The vacuum is generated via an industrial air mover, which is nothing more than a vortex venturi. The venturi or vortex unit is about 4-5 inches in diamter and 12 inches long. You hook it up to your air compressor and the venturi effect pulls a vacuum inside the drum. The hose is just a vacuum cleaner type hose, maybe a little beefier. At the bottom of the tank there is a spigot drain. The entire assembly sits on a wheeled cart so you can roll it around with ease. It wouldn't suck up rocks, but it will suck up sand and gravel and fish if you're not careful.

The concept is quite novel. No moving parts, no filtration items, no priming, no electricity. But, you do need a powerful air compressor with a large volume tank.

Not sure if that is useful to anyone, but I thought you could entertain the idea and come up with a design that suits your purposes with some of the information.

Catfishnut

Catfishnut, do you have any pictures or video of what you are talking about? I'd love to see what you are doing and add to my list of brainstorming.

Currently, I'm working on my own Airlift Pond Vacuum and it's working out quite nicely...the problem is the weight of the water in the discharge hose...maybe your project could give me some modification ideas...??

Here is mine, please tell me what you think.

Thanks in advance,

Wayne, SC

 

[Event Horizon]

I really like what you are doing, please keep me/us updated on your progress! Waterbug is very knowledgeable in this stuff and I'd take his advice to heart.

You can tell I am listening to Waterbug :bowdown: by looking at the evolution of my drawings. When I finally build this I will be sure to take pictures, and report how it works for me.

 

[Catfishnut]

Divedaddy,

Here is a link w/photo from the mfg's website (Nortech Vacuum Products) of their vacuum unit for a 55 gal drum. This is the thing we have at work for spills. You cannot tell a whole lot from just a small pix, but that silver unit atop the lid is the total heart of it. I would love to have one of these at home, but they want something like $1,100 for this! I think not.

http://www.nortechcorp.com/vg55.htm

This is a link w/pix of a device that may be similar to what is inside the unit powering the vacuum above.

http://www.exair.com/en-US/Primary ...mplifiers/Pages/Adjustable Air Amplifier.aspx

catfishnut

 

[divedaddy03]

Divedaddy,

Here is a link w/photo from the mfg's website (Nortech Vacuum Products) of their vacuum unit for a 55 gal drum. This is the thing we have at work for spills. You cannot tell a whole lot from just a small pix, but that silver unit atop the lid is the total heart of it. I would love to have one of these at home, but they want something like $1,100 for this! I think not.

http://www.nortechcorp.com/vg55.htm

This is a link w/pix of a device that may be similar to what is inside the unit powering the vacuum above.

http://www.exair.com/en-US/Primary ...mplifiers/Pages/Adjustable Air Amplifier.aspx

catfishnut

Catfish,

Very interesting concept, I'm guessing you are right in saying that the vacuum is created with something similar to that air amplifier from exair.
I've always been fascinated with the concept, even before the Dyson air multiplier fan was on the market I was thinking about this concept and now I'm still trying to figure out other applications.
Do you think that this would work to maintain a vacuum underwater and have you seen any video of it (or similar) in action?
I think you're on to something!

Wayne

 

[divedaddy03]

You can tell I am listening to Waterbug :bowdown: by looking at the evolution of my drawings. When I finally build this I will be sure to take pictures, and report how it works for me.

Yes, Yes, Yes Please do! I love this project, and I'm excited to see how it performs!

Wayne, SC