this is the first year i have had a pond, i have done all the treatments i am suppose to, however i live in michigan and at this time i have my rock waterfall working, i bought a 750 watt pond heater i will place in pond at first ice, my question is this, my koi and goldfish hang out under the waterfall rock all the time now that the water is cold and don't really come out which is no big deal, i just want to make sure they are ok, should i have a supplemental heater to keep the water at a certain temp or will the 750 watt floating heater work ok, it is suppose to keep an opening in the ice all winter
thanks
dave
gowen mi
thanks
dave
gowen mi