Building a new filter system have some questions

[JohnHuff]

Somehow it makes more sense to have the small gravel at the bottom and the big rocks on top and have it a downflow filter. Then to clean, bubble the water from underneath. This way the debris won't pass openings which are smaller than them.

The way it is set up. The bigger rocks are at the bottom and small gravel at the top, and it's an upflow filter. But when he does the bubbling action, the big debris which is caught at the bottom will need to go through the medium and small sized openings to reach the exit at the top.

 

[Dave's pond Indiana]

Just a suggestion I think this is a real good design, I think it would help to install a drain valve at the bottom to drain the heavy muck that will gather at the base and open this valve before you turn the pump off and it will discharge the muck. Then close the valve, turn the pump off and back flush as seen in the video.

 

[JohnHuff]

Just a suggestion I think this is a real good design, I think it would help to install a drain valve at the bottom to drain the heavy muck that will gather at the base and open this valve before you turn the pump off and it will discharge the muck. Then close the valve, turn the pump off and back flush as seen in the video.

Agreed, also makes sense to add water from the top to flush that heavy muck out. In general, the flushing should be done in the opposite direction of flow.

 

[morewater]

Hi all,

I am ahead of myself as there is still 2ft of frozen packed snow around my pond, but i want to build a more efficient and easier to maintain filter system. I saw this video and thought the cleaning method was really clever.

So I want to build something similar, just a but smaller. my question is more related to the media inside the filter. This is my rough design....



I am going to use a 32 gallon trash can, and these materials... (all from home depot)








My questions are.

Am I using the correct materials?
Are the ratios ok?
And is the order correct? Big gravel first filter, then pea gravel next, then lava rock?

This is going to be in addition to my skimmer, which I am still working out how to make it easier to clean.

I appreciate any help, criticism if am I completely wrong please tell me,

thanks
jp

 

[morewater]

Use 40gallon plastic drums, you can find them almost anywhere. Wine store outlets, dock material stores. You can even find them on Kijiji.

Take a plastic milk carton (you know, the big one that has all the holes in it - I don't advocate theft from the grocery store..., cut a hole in the top of it to allow for a 2" ABS pipe (from Home Depot or wherever) to reach to the bottom of the plastic drum. Fit an ABS "T" on the end of the pipe. Attach two shorter pieces of ABS pipe to the "T". At the end of each of the shorter pieces, attach a 45 degree ABS elbow. At the top of the "T", attach an ABS hose connector. All this stuff is available at Home Depot or any hardware/plumbing store.

You'll end up with what looks like a large "T". The concept being that when the water is forced through the pipe from the top of the barrel, the water will "vortex" as the drum is being filled and must pass through the filter media before reaching the outlet. Use filter media mats. They're easy to take out and hose off when dirty.

Use a plastic bread holder (you've seen them in the grocery stores, again I don't advocate theft from the grocery store , cut them round to match the inside of the drum, cut a hole in the centre of it to accept the ABS pipe. Place it on top of the plastic milk carton.

Using a hole saw, cut out the desired number of outlet holes on the plastic drum. Bring the liner up to the lip of the plastic drum. Cut holes in the liner to line up with the holes in the plastic drum. Use 2-piece ABS fittings (they're threaded), push the one piece through the liner and into the drum, thread on the other piece inside the drum. Voila.....mechanical filter.

They work great, they're cheap and easy to maintain. Sorry, no pictures (mine are covered in snow).

Oh yeah, you might have to cut the plastic drums to open the entire top. Keep the cut-off "tops" to use as lids.

 

[Waterbug]

The order you put the materials in doesn't really matter. When the air is turned on the material fluidizes, or should. That means everything moves, almost like a washing machine. When the air turns off the material falls back out of suspension and sorts itself into layers. That's why it doesn't matter what order the material goes in because the filter will layer the material itself.

It's kind of a whole deal getting the amount of air right. Has to be enough to cause the material to fluidizes or it doesn't clean very well, but not so strong that it blows sand out of the barrel.

Lava rock would require a lot of air to be moved. You might want to reconsider that.

There's a ton of info on these filters, they've been around awhile. Often called "sand & gravel filter". They are meant to be used to "polish" water meaning there are other filters before the S&G to remove larger stuff. That allows for cleaning less often so only need cleaning every week or two depending on the pond. They can be used by themselves but may need to be cleaned much more often.

 

[archimedes]

I have a filter similar to this.

It's a 55 gallon barrel

Large rocks on the bottom, medium rocks above that, pea gravel above that, and very course sand above that.

There is an air manifold in the bottom for cleaning the rock.

The water is pumped in the bottom and flows out the top by gravity.

The waste drains to the garden by a separate pipe.

I clean it once a week, but probably could go much much longer. But it's so easy to clean I do it once a week. My hand don't even get wet.

So far my water is crystal clear.

P.S. this filter is preceded by a settlement tank that filters out the larger stuff first.

 

[archimedes]

The order you put the materials in doesn't really matter. When the air is turned on the material fluidizes, or should. That means everything moves, almost like a washing machine. When the air turns off the material falls back out of suspension and sorts itself into layers. That's why it doesn't matter what order the material goes in because the filter will layer the material itself.

this is so true. I was so worried about what would happen when I blew it out the first time. I thought I was going to mess it up. But in fact the larger heavier rocks settle to the bottom anyway.

It "feels" better to layer them while you're building it, but they will sort themselves out anyway when you fluidize the filter when cleaning.

My barrel is translucent, so I can see the layers in the barrel. When I was building it I filled the layers slight uneven by accident (not that it mattered). Now, after cleaning it multiple times, the layers are all perfectly sorted by size..

 

[morewater]

Use 40gallon plastic drums, you can find them almost anywhere. Wine store outlets, dock material stores. You can even find them on Kijiji.

Take a plastic milk carton (you know, the big one that has all the holes in it - I don't advocate theft from the grocery store..., cut a hole in the top of it to allow for a 2" ABS pipe (from Home Depot or wherever) to reach to the bottom of the plastic drum. Fit an ABS "T" on the end of the pipe. Attach two shorter pieces of ABS pipe to the "T". At the end of each of the shorter pieces, attach a 45 degree ABS elbow. At the top of the "T", attach an ABS hose connector. All this stuff is available at Home Depot or any hardware/plumbing store.

You'll end up with what looks like a large "T". The concept being that when the water is forced through the pipe from the top of the barrel, the water will "vortex" as the drum is being filled and must pass through the filter media before reaching the outlet. Use filter media mats. They're easy to take out and hose off when dirty.

Use a plastic bread holder (you've seen them in the grocery stores, again I don't advocate theft from the grocery store , cut them round to match the inside of the drum, cut a hole in the centre of it to accept the ABS pipe. Place it on top of the plastic milk carton.

Using a hole saw, cut out the desired number of outlet holes on the plastic drum. Bring the liner up to the lip of the plastic drum. Cut holes in the liner to line up with the holes in the plastic drum. Use 2-piece ABS fittings (they're threaded), push the one piece through the liner and into the drum, thread on the other piece inside the drum. Voila.....mechanical filter.

They work great, they're cheap and easy to maintain. Sorry, no pictures (mine are covered in snow).

Oh yeah, you might have to cut the plastic drums to open the entire top. Keep the cut-off "tops" to use as lids.

 

[morewater]

Here's a diagram. Cheap and easy to build. Easy to clean (I pressure wash the filter mats a couple times a season). Shop-vac it out for the winter and put the lid on it to keep the weather out. I've used 40 gallon drums, but you could use pretty well any type of a rigid container (Rubbermaid feed trough, sump pump chamber, whatever).

 

[cheeseyfella]

I have a liner to replace in 2 weeks so not fun at all .I love ponddiggers video's especially the one I mentioned with the pigmy goat stealing the show .Her name is Billie Jean .Here winter is almost over ,after to night unless we get a bad March which I hope we don't .Your pond looks like a fun swimming pool .I also noticed you did it above ground .Mine is half and half .

mine is half and half too, it is 2ft above ground, but then in the middle goes about 1-1.5ft below ground in the hole from the original pond.

 

[cheeseyfella]

Interesting filter. I wonder how the air is bubbled back up at the bottom. Is it PVC pipes with a lot of holes drilled in them or what? He doesn't say.

in one of his other videos he shows what he did. He made a hexagon shape using 45s and drill holes in them, so when you push through the pipe, it blow up all around the base of the filter.

 

[cheeseyfella]

Cheesyfella,

I may have misinterpreted your goals at the onset. The diagram appeared to me to have the smaller gravel first. I had to review the video again to refresh my memory of the construction (I had watched it before a few times, but forgot which one it was). I see that he was placing the lava rock on top so that it can be removed and rinsed during the purge cycle and that the larger rock were at the bottom, finer rock and gravel above. That is the way it should be. I got the wrong idea and thought it was set up the other way around.

The purge cycle with forced air and water is exactly what you need for cleaning. That flushes the trapped sediments out to the drain and the air also re-expands the bed material. over time, the bed wants to settle and become tight or impacted. The flushing water and air lifts the gravel bed and unsettles it so that it is more porous and water can flow through with less restriction.

The only other comment I have is something that I observed from Eric Triplett (The PondDigger) on youtube. In one of his pond construction videos he stated that lava rock in bags is not as efficient or as effective as loose lava rock. In that pond build, he used nothing but lava rock in a Helix brand waterfall filter. It still had the provision to purge the filter with air and water.

You might wish to google that up and watch it for tips to apply to your design.

Good luck with this project and hope to see great results come construction time! Please post pix or vid's of your process and assembly.

gordy

thanks again, I was going to work on the premise mention earlier about using stone size in the same way as filter size bigger filters getting smaller, but the adding of lava rock at the top for more biological type filtering. I was going to leave it unbagged and rely on the air system to help clean it out. As soon as I get a barrell I will make a start and document it and any changes I make for everyone.

 

[cheeseyfella]

Just a suggestion I think this is a real good design, I think it would help to install a drain valve at the bottom to drain the heavy muck that will gather at the base and open this valve before you turn the pump off and it will discharge the muck. Then close the valve, turn the pump off and back flush as seen in the video.

I agree and this is something I have factored in for cleaning and possibly for draining the filter for winter

 

[cheeseyfella]

The order you put the materials in doesn't really matter. When the air is turned on the material fluidizes, or should. That means everything moves, almost like a washing machine. When the air turns off the material falls back out of suspension and sorts itself into layers. That's why it doesn't matter what order the material goes in because the filter will layer the material itself.

It's kind of a whole deal getting the amount of air right. Has to be enough to cause the material to fluidizes or it doesn't clean very well, but not so strong that it blows sand out of the barrel.

Lava rock would require a lot of air to be moved. You might want to reconsider that.

There's a ton of info on these filters, they've been around awhile. Often called "sand & gravel filter". They are meant to be used to "polish" water meaning there are other filters before the S&G to remove larger stuff. That allows for cleaning less often so only need cleaning every week or two depending on the pond. They can be used by themselves but may need to be cleaned much more often.

I will start using my shop vac and if more air is required, I will fit an attachement to the 1in pipe and use my compressor, getting the enough air should be ok, but getting the right amount so that I dont blow everything out will the challenge