adequacy of bead filtration?

[D&RW]

why closed, but openable? i'm trying to imagine the function / operation. water drawn off pond comes to this open barrel (where's Rube G. when you really need him pond side pipe is connected by standard threaded MPT fitting into say a bulkhead. Barrel is filled with water and media prior to start up. Pipe then goes out other side of barrel via same set up to pump.

Turn on pump in open system and I'm thinking maybe the flow from the pond into the barrel won't be able to keep up. barrel would get emptied and pump would suck air. IF the water would keep up, that'd be fine. It'd be easy to clean, particularly if a drain was installed.

Second reason, seems like the suction of the bottom drain created by an open barrel like this would be significantly less than a closed system ergo reduced function of the BD.

I'm trying to visualize a tubular filter. 6 " PVC pipe, say 2-3 ft long. Both ends have reducers from 6 down to 2 ". Take a 2 in piece of PVC shorter by a few inches and cap one end. Drill multiple holes all around it and place a MPT adapter on the other end. Place the two inch inside of the 6 inch and screw that half-way into the pond side reducer from the inside using enough pipe dope or telfon pipe to make it watertight. Fill the area between the two pipes with 2-3 ft long strips say 1in X 1in of coarse filter material. screw the inflow and outflow pipes into each reducer at either end. Joila.

There are two issues. First being sure the pond side reducer has enough thread to accommodate two male pipe threaded fittings and still be water tight. Second, how to make the other side "openable". So far the reducers I've found are slip and would need to be glued, ergo not openable. If I could find a FPT-MPT one I'd be all set. Just screw off the pump side reducer, pull out the media and hose it down. Another approach would be to find a 6 in. Fernco and cut the outside 6 in. pipe and the put it back together with the Fernco.

I just checked. Ferco does make a 6" to 6 " coupler.

whattya think?

 

[nc0gnet0]

Let me get this straight, you have a bottom drain and an external pump. You also have a bead filter. So your setup is bottom drain > external pump > bead filter > return.

You wish to add some sort of prefilter to protect your external pump or to reduce sediment to your bead filter?

In other words do you want the prefilter before or after your pump?

Your pump should be able to handle all but the biggest of solids, a simple screen over the bottom drain should prevent the occasional pebble etc that could damage your pump. Trying to use a barrel would require the use of a gravity type feed to a filter pit that was self leveling (no overflow) and capable of at least the same volume that your pump puts out. And if the barrel becomes partially clogged (or any prefilter placed before your pump) your pump may run dry.....not good.

If your looking to add the prefilter after your pump it would need to be inline and pressurized, a barrel filter won't work.

 

[koikeepr]

Right. The issue is the gravity feed problem. As I said, Aqua Art does sell a protective screening cover, but you can likely DIY something too.

I'm not even sure how the BD is working effectively going up and over the edge, because that's not really how these retro drains are meant to function...

 

[D&RW]

the bottom drain isn't going up and over the wall. It's plumbed straight into the skimmer, under water about 10 inches.

Yes, even though I'm no expert on barrel filters, my intuition and basic logic say one wouldn't work in this application unless it was a closed, as close as possible airtight barrel.

I'm scouting alternatives, but in the meantime I'll just stay with what I've got. It was working fine last year, just kind of a PIA to pull and clean.

 

[nc0gnet0]

Can you draw out what you got? I do not think anyone has a clear picture on how your current setup is plumbed. I do know that bead filters need to be pressurized to work. I do not think any of the DIY barrel filters will be able to handle the amount of pressure needed to operate the bead filter correctly. I know of ony one filter capable of doing what I think you want it to do, but they run around $900.........

Are you worried about wear and tear on the pump or are you just trying to limit the amount of debris that enters the bead filter?

 

[nc0gnet0]

I'm trying to visualize a tubular filter. 6 " PVC pipe, say 2-3 ft long. Both ends have reducers from 6 down to 2 ". Take a 2 in piece of PVC shorter by a few inches and cap one end. Drill multiple holes all around it and place a MPT adapter on the other end. Place the two inch inside of the 6 inch and screw that half-way into the pond side reducer from the inside using enough pipe dope or telfon pipe to make it watertight. Fill the area between the two pipes with 2-3 ft long strips say 1in X 1in of coarse filter material. screw the inflow and outflow pipes into each reducer at either end. Joila.

I have something almost like this with the exception the pvc houses a filter sock. But I keep imaging scenarios where any pre-flter you build becomes clogged and the filter runs dry or partially dry and cavitates and burns up. In this case you have done the exact opposite of what you were trying to acomplish.

Myself I am really starting to consider going with a Bakki shower over a bead filter in my new build.

 

[D&RW]

Uh, this is likely a non-problem. concern was to limit debris going through pump into bead filter. since there is no settlement chamber i figured i'd do what i could to reduce the debris, but there are no or very, very few pebbles or rocks and i vaccuum a couple times during the summer anyway.

if one reads the aquaart retrodrain materials they state that these drains are "compatible with any type of matala like filter material. i haven't actually asked them if they mean sticking a round piece of filter material in the drain like I have or what.

I agree w/nc0gnet0 in the concern about clogging a prefilter and starving the pump. except for the pipe within a pipe design, all of the others i've come up with bear this risk. i'll see what the final configuration of the bottom drain hook up is and if it's as easy to remove as it was last summer, i'll just stick with putting the blue matala filter material in the BD and calling it good.

I do have an underwater camera, but don't know if I can get a pic. i will do a drawing and post it just for fun.

 

[D&RW]

So, now the bottom drain is in and it was way too difficult to mount to want to remove it periodically to clean out filter material. I'm back to the drawing board on a prefilter.

Assuming I decide to go ahead with some kind of prefilter, I think what I may do is simple and not expensive. I'll take a 6 inch diameter piece of PVC probably about 2 ft long. Place reducers on either end going from 6 to 2 inch. on the inside of the pump side of the 6 inch pipe, I'll put a piece of circular grate with maybe 1/2 holes. This is to keep the filter media from going through. Then I'll take the blue matala filter material and cut it into 1 in X 1 in strips about 1.8 ft. long. I don't want to pack the 6 in pipe tightly with these, rather leave some room around them. I could see leaving at least an inch all the way around, so the bundle will be about 4 inches and not bound. Each strip will be loose.

I'll cut the 6 in pipe in 1/2 and use a 6 in fernco to put it back together. This will allow for cleanout now and then.

What I envision here is not total filtration of the path of the water. My expectation is it will catch "some" of the stuff coming through, but not all. And IF the filter strips get really clogged with stuff, there still should be room for the water to go through, i.e. around it. I expect to clean it out maybe weekly or bimonthly if I find it isn't clogging up too much.

If I do it I'll probably check it every two or three days at first. check the progress. I'm hoping the grate itself won't get clogged because so much the stuff coming through is being caught by the blue filter material up stream. But if it is or the system doesn't look like it's going to work i'll toss it.

 

[D&RW]

Hey, check this out. You know those intake strainers they make for pump lines that go straight into ponds. They are wider at the top and slope in to the female thread fitting. I have one in 2 in. I used on my other pump. the top is 5 inches exactly. so, I'm thinking of getting a 2 in female w/reducer to 1/5 in slip. I'll slip a small section of 1.5 into the pump side line inside the 6 in pipe. This will make a much better grate than what I had in mind. drawing coming.

 

[D&RW]

illustrations and photos

 

[koikeepr]

i wonder if you could rig this up to fit under the BD so that you wouldn't trap big crap up into. That would certainly prevent anything substantial from getting up in there, and then you may not need a prefilter. Not sure if it will fit under there tho.

 

[D&RW]

you must mean in line between the BD and the skimmer--the BD is designed, I think, to sit flush with the small openings providing suction. I don't think there's six inches of clearance even with an extra cupped out low place. Besides, most of what I'm thinking of filtering might make it through those slots.

I still think it's kind of a non-problem. I mean that's what the bead filter is supposed to do, eh? Filter. Backwashing should get rid of most of whatever accumulates. So, I'm going to wait and see until I clean out the bead filter at the end of the fall season. Then, IF there's a lot of crapola still in it, I'll build the prefilter.

rw

 

[koikeepr]

Yeah, i was talking about under the BD itself--right on the intake hole under the BD. You're probably right in that there is likely not enough space under the BD to fit that thing.

 

[nc0gnet0]

Take a waste basket made of wire mesh, invert it and place over bottom drain. Plenty of surface area to prevent total clogging and much less a PITA to service........

 

[DrCase]

I am still waiting for the pics to see what you have to work with..
i have been following every-ones suggestions over the weeks
Can you use a leaf trap like you would find on a pool pump, less the pump..
It would keep every thing pressurized, and would be a lot easier to clean