Expanding the Koi Pond

In the Fall of 2005 we expanded our fish pond from about 900 gallons to about 4000. Our koi had grown too large and we simply had too many for the old pond. Also, we didn't have a strong enough filtration system to support the fish population. So with the help of James Yu from Atlanta Koi & Garden, we expanded the pond to be about 4 times the size of what it was before.

Below is a quick summary of the process that we undertook in the expansion. Curiously enough, a blue heron visited us on the morning that we were moving the fish into their temporary pool inside. He did get one goldfish, but the dirtiness of the old pond helped hide the rest. Hopefully, the new pond will give the fish more room to evade.

Here is a picture of our old pond. It was attractive with many plants, but had a small waterfall and a simple in-pond filter unit. The pond also had large rocks on all the inside of the liner, thus giving the fish waste plenty of places to accumulate.
Top view of the old pond. There's a good view of some our fish here. Our biggest koi are about 18"-24".
The fish's temporary home. We purchased an in-ground pond that holds 225 gallons from Home Depot. Mr. Yu advised us that with a good biofilter in it, and with frequent partial water changes, the fish would be OK for a couple months. They actually made it just fine. Clearly, it was cramped quarters for quite a while, but it was nice and warm and quiet and dark for them. We cut back on feeding to once a day too.
We had some help moving out all of the old rocks and taking the pond apart (but not by the guys shown here :^). After that, the first main task is digging the new, larger hole in the ground. Christy did the yeoman's share of that work with John providing expert supervision.
Another angle of the larger pond footprint. We had to take it out further into our backyard grass. That's our Chinese Windmill Palm in the front right.
The next step is putting down the black pond liner. Actually, under the liner is a fabric pad to protect the liner from sticks, rocks and sharp objects puncturing it. In putting down the liner, the trick is to remove the wrinkles as much as possible. The rocks around the border and the temporary water inside then help keep it in place.
Just another view of the liner put down. Our Orangeola Japanese maple tree is in the front left foreground.
Our new extensive pump and filtration system installed by Mr. Yu. It includes 2 UV lights, a leaf trap, and a large filter filled with beads. The system is easy to clean and flush.
The initial water has been drained so the bottom draining filter can be put in. It's secured with some rocks.
The pond's been filled back up with water and the filtration system has been turned on. The pipe feeding the water back into the pond is simply sitting in the back corner where the waterfall will be. You can see the first few goldfish we moved back into the pond. We made sure to condition the water and run the system for a few days before putting any fish in. We also then only added a few fish at a time.
A front view with the temporary pipe position. You can see the pipe taking water out of the pond in the front right corner.
A back-corner view of the pond at this point, looking in from our back patio. Fall is here and the leaves are changing color.
Here Mr. Yu is starting to construct the waterfall. It was built up on some dirt and cinder blocks. The fish are curiously checking out what he's doing. That's a Nigrum Japanese maple in the back right and a Waterfall Japanese maple in the center.
The new waterfall is coming together. It's important to make sure that the liner is behind all the flowing water and none is leaking out.
A side view of the waterfall in progress. That one big rock stuck out too far on the left though. It had to be moved.
OK, now it's looking better. The waterfall is pretty well set. Now all that remains is finishing the small rock wall around the pond (another job for Christy). Note the color change on the trees now. Fall is really setting in. Also, the initial expected algae bloom is starting to happen in the pond. That's OK for the fish.
The completed pond. Everything's in place and the fish are happy. We will be adding some more plants in the spring when things warm up.
Front view of the completed pond. (Note the lack of leaves on the trees.) The new pond is around 4000 gallons we estimate. The blue heron came back and took two more of our fish, so we have just put a net over the pond. We were hoping it wouldn't come to that, but it appears to be necessary.
Here is the completed pond in the spring. The Louisiana irises are blooming and all the leaves have filled in on the surrounding trees.
A top view of the pond in the Spring. You can see our various koi and goldfish. Our new alligator (Wally) is patrolling and keeping an eye out for the heron.
A summer view of the pond. The plants inside have grown a lot and the crape myrtles next to the pond are blooming.