We don't always have really low temps in Georgia, but sometimes it will dip into the teens. I've had problems with my waterfall in the past freezing up after having low temps for several days. The water freezes in the stream part and the water flows out over the ice, which drains the pond, if I don't notice it. Is it ok to turn off the pump leading up the hill to the fall, will the pump be ok, or would it freeze inside. It sits to the side of the pond, buried partway and has water in it.
We just came out of it being so cold over the past few weeks that we were happy when it got up into the teens. Yesterday it was 8F at 8:30am and it was 53F at 11:30am... eesh gotta love it! But the past two days have done wonders for thawing things out again.
When it's that cold out, I keep the ice cut back around the waterfall, but otherwise keep everything running all year. No overflows as long as I keep the splashing water flowing back under the ice instead of over the top of it. However things finally thawed enough that I was able to get the filter media out of one of my barrels tonight and drop in the big heater. Looks like it's going to be a cold Winter, so may as well be ready for when the temps drop again. The heater adds just enough to keep the waterfall from freezing up without so much manual intervention. Tomorrow I'll get the heater coils positioned so they don't melt any of the PVC or the barrel itself, then I just have to run an extension cord over to the falls when needed.
in reality you should switch off the water fall otherwise you run a risk of your super chilling your ponds water which is something you really should avoid doing .
In reality you switch your water fall off , then should put an airstone into the pond hanging about 10" from the bottom of the pond.
Your filter should be turned either down or off for the whole of the winter period up into early spring when temperatures start to rise again into 10c and above .
We run a formal koi pond in the UK we have everything insulated against the cold and cover our pond and filter housing with polycarbonate roofing sheets .
As a result even at -10c and bellow our pond never goes bellow that of 7c , we do water changes everyfew weeks via the bottom drain of the pond and drain the vortex , our water change is 40% of the ponds water using the trickle method of warming the water as it enters the pond.
Being a formal koi pond we dont run a waterfall but do know all about the superchilling effect of waterfalls from the many books weve read ..
Costia can become a threat at such low temperatures as it likes waters of 2c and above.
You may then find your fish have come down with it , giving you the added problem of treating it , if left untreated it ,may then cause fatalities in your younger fish which would be a shame .
Dave
