I need help in designing a swimming pond, this is what I have, think so far. We are on 10 acres in MN we have a man made pond with a mostly clay bottom, cattails and arrowhead plants, built by the previous owner for the wetland bank. In the spring and wet times it overflows to create a small creek. We built a new house and dump our open loop geo thermal into the pond. As soon as I can get gutters on that water will go into the pond too.
I started digging a square-ish dish shaped pond 35'x35' in the line of the creek about 50yards from the big pond.
What I envision, plan is a center depth about 24", EPDM liner, pond divided in half by sand bags within an inch or two of the surface, with 1/4" clear gravel in the half with plants, under the gravel some pvc piping to pull water through the roots and gravel with a small pump. Sand in the swimming half and a beach. The seasonal creek would com into the plant half and exit the swimming half. Koi or other fish.
Other than the basic question is this a good plan? Is the piping under the gravel the best way to circulate the water? Should I put bentonite clay under the liner or just a fabric, carpet or newspaper? Will the creek cause a water chemistry problem?