Monday, June 2, 2008

A HOME FOR THE KOI

In the backyard, we built two ponds using railroad ties and rubber liners, one for the koi and the other for plants and goldfish.

Actually the second pond is part of the water conditioning system. There is a siphon that takes water from the larger octagonal pond (in the foreground of the photo) to a stand-pipe in the smaller rectangular pond (in the background). The height of this stand-pipe and the resistance to water flow through the pipe determine the level of the water in the larger pond. Water from the second pond is pumped back to the larger pond. The faster it is pumped back, the higher the level of the larger pond, the greater the siphon pressure, the greater the flow to the smaller pond. The system is in dynamic equilibrium.

There is also a larger pump taking water from the large koi pond through a filter, back to the large pond. This filter is occasionally backwashed into the garden or lawn. Both pumps and the filter are located in the garage. The pipes are buried in the lawn.

Our long range plan is to enclose the railroad ties in a sheath of cedar shingles and place redwood boards on top, matching the look of part of the porch railing being repaired.