Pond Pump

I have a 15′ above ground pool, avg water depth of 42″, what size aeration pump for gold/koi? Mild climate and low population.

Hello, I have a small patio pond (80 gallons) which I would like to keep completly ice free over the winter in a cold climate (7000 ft). What heater should I use? Also, should I keep the circulating pump on all winter? Thanks!

We need a way to pump water from the trash can holding our filter backwash to our garden. Can you recommend an inexpensive pump or device? I saw a venturi pump. Is this effective? I tried to siphon the water with a hose and it didn’t work.