I have a small water garden consisting of 2 preforms with miniature gravity fed filtration systems. The reseasons I don't build a big pond are numerable but was fascinated with the gravity feed filtration so I built a small one 5 years ago. It operates on all the same principles, it's just scaled down. As with large ponds, it's never done and I enjoy the heck outta tinkering with it.
In 2007 I wanted to add filtration to my upper pond and had room for two 5 gal buckets. I decided on an SC that would be an 8 gal bucket, which is the same diameter but taller than a 5 gal, with tangential inflow and med solids/bio using a bag of shavings just below the outlet. The next 5 gal bucket would have a quilt batting bag on the inlet for fines and the pump in it.
I dug a hole and added a uniseal to the preform. I got a 8’’ pvc pipe cap to use for a retro BD.
The area is small..it’s a pondsai..... and I didn’t want a great ugly cover so I started working with a cardboard template for a nice curvy shape.
I actually cut out a nice curvy plywood cover per the template but never got around to mosiacing it. I realized that I needed some kind of wall to around the pit. I played around with a scrap of fiberglass shower liner and covered the plywood with edpm and left it at that.
Summer 2007 ended up being a rough year, my old dog Maggie died.....
she was a 12 year old GSD, St. Bernard/chow mix and a character until the day she dropped.
.......and my new dog Rascal, a badly neglected 6 month old standard poodle came to live with us, so nothing more happened with the pit that summer.
Spring 2008 was designated filter pit build time...but the engine in my 1979 JD L&G Tractor bit the dust ......
.......and so rebuilding that trumped working on the pit.
Spring 2009!! Finally I have the time.....
.... still unemployed since June 2008, and energy to do the curvy wall build. I had been thinking all this time about how can I do this, I am a design drafter by trade and have much experience in what looks good on paper cannot always be built. I knew the best way was to do a poured wall, but wasn’t sure how to build the form. So I started playing around with how tight a curve can shower liner sheet be bent to, I did some testing and decided it could be done. I cut out the shape for the inner form out of ˝’’ plywood and screwed the shower liner to the edge. I had needed to level both preforms and decided that the edge of the upper pond would be supported on a 2x4 that sat on the new wall. So I got the 2x4 in place and cut 2 vertical 2x4s to hold it up and those verticals became the wall ends part of the form by screwing the shower liner to them.
I used blocks of 2x4’’ screwed to the inner and outer form to position the outer form. The gap in the outer form would be filled with another piece of shower liner. I then realized I maybe should have dug some deep column ties to prevent frost heave before I screwed the outer form in place. I started digging a hole for the columns by sitting inside the form, thinking I need a garden trowel with a really long skinny handle because the post hole digger would not fit thru the 3 ˝’’ gap between the inner and outer forms. Well the trowel had a 3/8’’ slot in the handle, what could I bolt it to?? I had a piece of 1 ˝’’ PVC pipe that just happened to be the perfect inside diameter for the trowel and a 3/8’’ nut!! Viola!! An 8’ handled garden trowel!!!
That’s all well and good for getting down in there and loosening the dirt, but how to get it out of those deep skinny holes??? Shop vac...with extra extensions!!! I also was able to fit a 1’’ pvc elbow and coupling to the end of the vac extensions to carve out a wider diameter in the bottom of the holes to act as a flange of sorts to help hold the column in the ground against frost heave.
OK, so what to use as mechanical reinforcement?? I thought even 3/8’’ rebar too hefty for such a small wall, plus I didn’t want to spend any more money or drive 20 miles to buy it. I had a bunch of 14 ga welded wire fencing from the 1000’ or so of fence I put up around my land. Specifically the roll ends that were too tight to unroll and use along the fence but that ahd been sitting in a shed for 10 years, I thought they might be perfect for column reinforcement..and I could use flat sections of the fence for the wall reinforcement.
At this point my concrete tutor suggested that I pour up to the blocks on the first pour and take them out before the second pour. So I got the column and wall supports placed just up to the blocks.
Ok, so now I am a fairly strong woman and I regularly take a couple of 80 lbs bag of mortar out of the van and ease it into the moisture resistant bins on wheels for my leaf making enterprise.....but hauling the 9 bags of gravel mix that I needed for this wall..... would kill me. So where my brawn ends my brain begins and I’ve always known that leverage, knowledge of center of gravity and a good hand truck are a girls best friend....you can drag, flip,tip and slide a lot of things that you could never (or shouldn’t) lift. BTW that pic is 15 years old, before the fat covered the muscles
Drag it to the edge until it slides down onto the truck.....Old Libby the Aussie and Rascal keep a close eye on me
wheel it up the ramp onto the deck...
...and tip it into the wheel barrow. This pick was the last partial bag for the pour, the full bags got flipped farther into the barrow and slit at one end and all the way down the middle length to empty the whole bag..
So after a nap to recover from 6 bags of concrete mixing I realized that I hadn’t put an opening for the SC drain in the wall. Darn!!! Well I knew from casting concrete leaves and some concrete carving ventures that after about 6 hours the concrete would be set enough to remove the form and do some carving. Luckily the drain hole needed to go right where the outer form patch was stuck in. So I got it in. I had planned to arrange the reinforcing mesh to go around this gap but now I will have to cut the wire and put some concrete patch around the opening to protect the metal from corrosion.
The first pour is done, the blocks removed, the gap closing outer form back in place, the rest of the wall reinforcing mesh in place and I am ready for tomorrow’s final pour.
3 and ˝ more bags and it was filled....had to add a bit of reinforcement to the outer form patch but it held fine.
At this point I was so pleased with myself, for finally realizing this idea that had been floating in my head for 2 years, my head and heart nearly burst!!!
Then I had to mow the yards before the looming thunderstorms...and then nothing but sleeping and eating the rest of the day to recuperate.
Although I did some tests to see whether the concrete would release from the shower liner
I was a bit nervous to remove the outer form, but it came off fairly easily.
The inner form I knew would have to be destroyed to remove it and I wasn’t sure how that would work out.
I borrowed a sawzall and cut the wood pattern as close to the screws as I could get then went at it with a hammer.
That and a few more cuts with the saw and it was all off.
I still need to do some patching where there were some voids in the pour..... it is now covered with a tarp to keep the 2 daily waterings from evaporating...and there’s the bases for the 2 buckets that comprise the filtration and get it running...then a cover that will be tile mosaic on plywood with lift off hatches for cleaning the filter...and I am also doing the other filter pit....so that’s it for now...more to come later.