Flirtations with Filtration

I've been noodling with homebrew filters since I was a really young guy ... sometimes because I'm cheap, other times because I was poor, and most times because I enjoy a so-called "disease" that plagues so many others: OCD. I'm sorry, but I fail to see the disorder part for me.

Anyhow ... the wife and I decided last year that it was time for me to get back into ponds/fish/water gardening/etc. and it was a koint Mother's Day/my birthday "gift." I've never worked so hard after the fact for a birthday gift ... ever. Well, most of you know how that goes. We opted to go the modest budget, "get yer feet wet" sort of project. Well before summer's end the plans for a new and improved backyard garden (replete with larger pond) was brewing in my head. Come Mother's Day this year my smooth talking (and perhaps a bit of masculine whining [there is such a thing, ya know?]) prevailed and a general building plan was "approved" by she who must be obeyed. Her last question (before the backhoe showed up) was: "Now what did you say about the pond that's there already?"

"We gotta rip 'er out, honey! It's in the way ..."

The look of fear on her face was understandable. Albeit a great deal on the smallish side, she loved it (and the fledgling fishy inhabitants) quite a bit. Anyhow, here's where we started. Not the best angle (makes it look a lot smaller than it actually is ... why do us guys even worry about such things? I dunno, but anyhow)

This pond was driven entirely by homemade filters, with the exception of the UV filter. The mechanical filtration was provided courtesy of a plastic box packed with unraveled "Lufa" sponges (that's actually a fantastic filter medium! Traps tons of gunk and does not clog up anywhere NEAR as fast as any sort of pads or other materials I've worked with). The water from that pump was pushed up through the UV and then to the tops of the twin "mini falls." The biological filter was hidden behind some grasses to the left of the picture (not in this pic). It was a 10 gal. bucket with lid and driven by a second pump. The bucket was filled with lava rock and topped with some lufa sponge material as well (top help cut down the amount of detritus trapped by the rocks. Final opinion on the set up: too much work!

So ... come Mother's Day 2005, it was time to dig 'er up and toss the bucket! (actually I saved the bucket to provide some sort of filteration/help to my poor fish who survived the winter and had to do a weekend campout in a really large cooler. After a few hours of digging, back filling, tamping down, stopping around and generall all-around cussing and sweating, we raised the old pond for its new job description: Waterfall basin and mega filtration system.

Here was phase one. As you might be able to tell, the old liner is reinforced with pressure treated 4x4's (left over from the next extension to the deck) and they were firmly seated in the ground with concrete. All said and told the upper lip was raised 42" off the ground.

Okay, now on to the fun part (and here's where the photography got even more sketchy) ... making the mega filter.

I purchased a 5,300gph pump and 30 feet of 2" non-kink pool tubing of from a local pond supply shop. Let me tell you, that ribbed pool tubing is a beast to work with ... those ribs do NOT like to stretch at all. Getting regular pipe and plumping fixtures to fit into that stuff is no fun whatsoever. Anyhow ...

Here's the general idea: within the now raised pond liner we have a storage bin that works as a mechanical filter. If need be, it also serves wonderfully for adding bags of activated carbon or whatever else suits your fancy to do some chemical filtration as well. My goal here was to collect dirt amd detritus from the bottom of the pond and trap it up in the waterfall basin somehow. I also wanted to not turn this raised waterfall area into a torrential whirlpool. The plastic storage bin needed to not only hold my filter medium, but needed to baffle the water movement as well.

Here's the tools you will need:

- Plastic storage bin, with latched lid.
- 10x10x8 (or 8x8x6) ducting hood
- Jig saw
- Marking pencil
- Drill with hole cutter bit
- 2" pipe connector



This message was edited Jul 25, 2005 4:23 PM

Here's the plan. The outflow from the pump enters the lid of the storage bin. The only exit point for the water is the ducting hood. The square box area of the hood is the PERFECT place to set filter pads! The volume of the storage bin allows the water pressure to dissipate before entering the old pond liner. Here you can see the fitting where the 2" hosing is connected to the lid:

But ... let's back to the construction of "Buck's Supersized Ghetto Filter."

First, mark where you need to cut the hole for the duct: I placed the hood inside of the bin and propped the "neck" part of it up with a wad of paper to keep it in place so I can trace it from inside of the hood with a pencil. I prop the neck so the ductwork will exit the bin parellel to the bottom instead of it tilting down.

After tracing the insde of the hole, I drill a small pilot hole at the very top of the circle that was traced with my marking pencil. That allows me to re-trace the hole on the outside of the bin so it is easy to line everything up. Cutting the hole out from the inside with a jigsaw would be a pain.

Aligning the inner-top part of the circular hole from the ducting hood immediately over that hole I drilled, I retrace the circle around it's outside diameter.

Now for more fun stuff: POWER TOOLS!

Break out the old jigsaw, insert the blade in the guide hole that was drilled out a few minutes earlier, and cut out the hole, making sure to stay just inside of the line drawn. If cut a little too tight, it's a lot easier to use a dremel or other tool to slightly widen the hole afterwards.

Measure twice, cut once. I had to create a lot of scrap material doing wood work to learn this.

All the same, it paid off this time.

And seen from the other side ...

Then I took the old drill and a 2" hole cutter bit and prepped the lid.

Again, in the picture above, that is the hole that will accept the pipe fitting that is attached to the pump. Water is drawn from the bottom of the pond and get dumped into the top of this bin.

All that was left was to cut and insert several layers of padding within the square part of the ducting hood. What I failed to photograph was the holes I cut in it (right where the square and tubular parts join). I strung some bylond weedeater "thread" through there to keep the filter pads from being pushed out of the tube.

Here's the pump, hard at work. That's roughly 5,000 gallons per hour and narry a surface ripple.

Oh ... the important part: getting rid of 5,000gph of water!

I used the same drill bit / hole cutter to set 6 two inch holes in the lip of the pond liner. There are these PVC pipe connector things that I inserted through each hole. The unthreaded side of these fittings is smooth (usually to attach some 2" PVC pipes). I pushed the threaded side through the rubber liner that would ultimately go up the back of the waterfall and then through the hard shell liner. I then placed a rubber washer over threaded part and then screwed the "cap" into place, thereby creating a secure, leak-proof fit. Here's where all that water exits the waterfall basin:

(I had to shut the pump down to take that pic)

Once assembled and tested I then make some stands out of 1/2" PVC piping to set on the bottom of the old pond liner so I can could set plants everywhere. Underneath the PVC planter stands is a BUNCH of material for our little bacterial friends to populate.

Being paranoid (and given to bouts of OCD on top of too much free time on the weekends) I also built another "gravity" type bucket filter behind this one that is dedicated to making a happy home for more bacteria.

Yesterday I spent no less than two hours inside of the pond. Cleaning filters, repotting and thinning, etc. When I climbed out, the pond was a MESS. It was a mud puddle, for crying out loud. Within a couple of hours the fish and I were enjoying some wonderfully crystal clear water.

In the end, my "mega filter" wound up not only looking a little less like a filter, but it also provide an immense amount of areation as well.

Not a great pic, but you get the idea.

ps: that was a new filter box being fitted into the old pond liner. The other one I made was the wrong size and shape. The picture a few posts up show it after I set it in but before I placed all the plants back in. The lid also serves as a nice plant stand as well! :o) There are about 20 plants in total that "live" up there right now. The water is wonderfully clean and clear, and I have had narry a problem with ammonia, nitrite or nitrates since this system has been up and running since mid May.

Want an opinon that's not as fishy? Ask him! :o)

Bogweed, we are kindred spirits. Ain't it fun messing around with all kinds of plasticy things, plumbing stuff, tubes and power tools? Yes, I believe you do have too much time on your hands! (Althought I can tell that you've got much more experience with this stuff than I do, since you were able to complete this job in one weekend and probably not more than 2 trips to the big box store. I don't even want to tell you how many hours I stood and stared blankly at the pvc aisle at HD. I still have a bag of stuff to return that I didn't use.I just can't bring myself to sort it out.) I don't know about the OCD, but I know there are drugs (whoops... I mean MEDICATION) for that problem,if it is actually a problem! . LOL You can rest easy knowing your little bacteria have plenty of homes to inhabit and that your water is crystal clear! Nice job there! And the frog to boot!

Here's the top photo of my 'home made' waterfall filter. Works great!