I'm also a zone 6 ponder - my ponds are on the north side of the
house and as such get no sun from middle of October until March.
I use the air stones too... but usually have to hook up the De-Icer
in mid-winter. The lack of sunlight is my problem
Also why it wont do any good to build a tent over the pond -
double chagrin (

I have two 1500 watt De-Icers. Am glad I
have them as back-ups.

Nedra in Missouri

Backyard Pond:
http://www.geocities.com/Heartland/Pines/4836
Lotus Pond:
http://community.webshots.com/user/nedra118

"ronm" wrote in message
.. .
I'm in zone 6 and last year the air pump couldn't keep up. Had to use a
deicer. Had a foot of ice on the pond. I didnt have to use it constantly
so
it will depend on the year. Last winter seemed a bit more severe.

"RichToyBox" wrote in message
news:uSJeb.10265$%h1.7466@sccrnsc02...
An aquarium air pump set with the airstone about 4-6 inches under water
should maintain the necessary opening in the ice to allow for gas
exchange,
getting rid of the toxic gasses and getting oxygen into the water. It
will
use considerably less electricity than the pond deicers and do the same
job.
Just be sure to cover the pump to keep it out of the elements, since the
pump is really designed for inside use.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"NauticalWheeler" wrote in message
...
I have a pond therefore, my dad wanted and now has a pond. He lives
in
zone 6. I live in zone 7 and never have had to worry about my pond
freezing. However, he will have much cooler temps. and his pond is
250
gal.
I am thinking a getting a pond de-icer for him. Can you give me some
thoughts on this one please and thank you! He has fallen in love with
his
goldfish and loves his pond!!
pond:
~~250 gal
~has goldfish in
~zone 6- VA
~protected from the wind

Lisa