Koi Rescue
Phoenix Arizona

Test Pond - small 200 gallon

On the front of our house, we recently added a courtyard wall. I watched the landscapers build it, and learned a bunch of stuff just in time to start working on my fish ponds.

Originally I was just going to make one big pond in the back, but my wife wanted a water feature in the front, and I needed some practice, so we decided to make a super simple small pond in the front. Just a rectangle of blocks, 2 courses high, will hold about 200 gallons. Main purpose is to get some experience, if it turns out crummy, I won't feel bad about busting it out, only going to use a few bucks worth of materials.

Speaking of materials, a neighbor suggested that I have everthing delivered, but I need the exercise and the delivery charge is more than the materials I am buying, so I am schlepping all the stuff from Home Depot in 800 lb loads, in my minivan. You know minivans are really pickup trucks with full weather covers on them. :)

To start, I setup the blocks where I wanted them and walked around to make sure I liked the placement. Then I staked and stringed the area, and scraped a couple inches down. The pad will be about 4" thick, but the perimeter will be 6" thick.

I re-setup the blocks to make sure I dug the right size hole.

Next I started working on the rebar ring that will be in the concrete. The rebar is supposed to be what holds the concrete together, concrete has a lot of compression strength but almost no tension strength, that is why it is so easy to bust up with a sledge hammer.

I am also putting piece of bent rebar that stick straight up, they will go into the voids of the blocks and hopefully be enough to keep the blocks from being pushed off the pad. Not only will the water be pressing against it, but I am sure many rear ends will sit along the perimeter of this pond.

Our courtyard wall was build with 8x8x16 blocks, which have a fairly large cavity to aim for with the stub up rebar, but the blocks I am using are the smaller 4x8x16 blocks. I tried using the wire to hold the rebar, but the stub-up pieces kept falling over and sliding around, so I welded them in place.

Here I put the form boards in place and the foreman is checking their level.

Here is some wire mesh to embed in the pad. It is supposed to keep the pad from sliding apart if it cracks.

Instead of renting a mixer, I bought one since I had a few projects coming up. Never used one before, this is the first couple of bags of conrete I tossed in there. It was rated for 3-1/2 cubic feet, and an 80 lb bag is 2/3 of a cubic foot, so it should have taken like 5 bags or so, but really it worked best with 2.

Also figured out that it is better to put the water in first, then drop the mix in. And while pouring it out into the wheel barrow, have a hose ready to wet the concrete that didn't get mixed right.

It took about 40 minutes to mix and dump the concrete, which was about 1/4 of a yard worth.

Then we smoothed it for another hour or so. Not sure if we are slow, or just having too much fun, guess it doesn't matter, this is a hobby and I don't think a concrete job is in my future. :)