Reel McKoi wrote:

"G Pearce" wrote in message
...
mid posted

I've kept koi & goldfish in Southern Ontario with temperatures down
below -20C and a foot or more of ice on the pond.

I use a bubbler to keep a hole open - originally I put an airstone on
it, but I kept losing the stone

Hi Derek - I used to lose the airstone sometimes as well (I used silicone
to 'glue' it to the airline) - I found the answer this year :~) - pvc
cement and I even tried to knock it off - & it's still on
=======================
I would think that would make it hard to check if the stone is getting
clogged, causing backpressure on the pump. Here the water is so hard the
airstones clog and must be replaced regularly.

I don't think that's a big problem - but I never had one in the pond long
enough to have experience in a pond. In my hard-water aquariums, air
stones always started emitting bigger bubbles as they got clogged.
--
derek