Following the good advice found on this NG, I went out and invested in an
aquarium heater for my primary. Cheaper than running a heater in the room
all winter. Plugging it in and getting it in there, though, necessitates
having the lid a touch open, and I'm wondering if that should be a matter
for concern.

For some reason, the rosé I'm working on now is fermenting very slowly (from
kit, ten days now and the SG has dropped from 1.070 to 1.015, but not low
enough to rack yet). My concern is obviously that the fermentation might not
be vigorous enough to push the oxygen out.

I'm contemplating making a notch in the side of the lid for the cord so I
can snap the lid shut and seal around the cord with poster putty or
something. Am I worrying too much?

Any innovative tips on how to use this heater in a carboy while preserving
airlock integrity?

Thanks all,

Matt