I am designing my pond for a pressurized bead filter with pump. These are about 30' away from my 4,000 gallon, 4' deep KOI pond. I want to run a 3" diameter pipe (for my BD) and a 2" diameter pipe (for my skimmer) each running individually, side-by-side, about 20" underground and joining together via a 3-way valve (to control flow) just before the pump.
Questions: First, do you think 1/2 HP pump should do the trick--considering all outflow will use a 2" diameter pipe and run about 15' back to a head height totaling 6' (4' high waterfall plus about 20" depth of pipe coming up from underground also....I am installing 3 jets so the water will be split to the waterfall and to the jets? Second, I live in CT and in the winter, things freeze. Should I shut down my skimmer and drain the piping near the pump to avoid pipe freeze or keep everything running? Third, how do people continue to protect and use the air diffuser pump in the winter? Does it freeze as it is open to the elements??? Forth, should I continue to run the pump and bead filter throughout the winter or just shut it all down and drop a submersible pump/filter into the center of the pond? What about the waterfall in the winter--shut it down and just run water through my jet system?
Lots of questions, thanks for your help!