Thanks for all the good ideas...I am thinking to build 2x4 frame and cover
with 4mil clear plastic and drape over pond, I have small air bubler pump
that I can use......the link Ingrid provided for low watage pond heater
does not work, is anyone famaliar with this heater
http://www.aqua-mart.com/flph.html or if I cover and put bubler in pond
should I put heater in as well? tia