Heating a Pond
Bob, How about heating my pond this winter, the family has grown fond of the fish and I don't have plans for an aquarium. I have been to the pet stores however, I have not found one that looks large enough for the pond. What would you recommend?
<... are you talking about just keeping the system from freezing, as to the bottom? There are ways to achieve this (straw, plastic coverings, a bucket 'o rocks... moving water... electrical heaters...). If wanting to keep this pond tropical, the cheapest route is to channel the re-circulated water about or through a water heater (gas powered)... and there are a few ways to rig a thermostat of sorts here... I would do a bunch of looking, seeing here... Have you read where I've been directing you? Particularly re basin design, pumping, plumbing... Please read: http://www.wetwebmedia.com/PondSubWebIndex/pdwintmaint.htm
I recommend not heating the system... for your livestock and pocketbook's sake... move the life "indoors" if necessary during the cold season. Bob Fenner>

koi /to be moved
hi,
recently, my 2 koi's have developed white spots on their bodies( eyes, tail, fins). they seem to have lost their appettite.
they probably have the "ich" like your faq suggest.
I bought them the medicine you suggested in the faq.
how do I avoid this problem in the future???
should I change the water more often??? should I change their diet???
will
>>
There are a few things you can do, though none/all are fail-proof. For one, do quarantine all new koi (and other pond fish) out of your main system for a good two weeks... keep them covered (to avoid jumping) and well aerated, and treat them as if they do have ich/external parasites... In your main system ich is best prevented by otherwise keeping water quality high and stable... Frequent, regular water changes, the addition of some salt during changes, vacuuming during warm months... regular backwashing/cleaning of filters... all contribute to environmental and limiting the presence and hyperinfectivity of disease-causing organisms.
Bob Fenner

DEAD KOI
Hi Bob, A couple of months ago, there were some major wipe-outs with koi wholesalers and hobbyists. A virus seems to be to blame. If someone wanted to re-stock their pond, the question arises of how to make it safe for the new fish. Of course, there are many different opinions, including draining and changing ten thousand gallons of water in a large pond. What do you think of the idea of adding a heavy dose of chlorine and letting the pond continue to run? A week later the chlorine should have dissapated and perhaps be ready for a couple of test fish. Sound OK to you? Harry
>>
Good to hear from you Harry... ah, yes, the every few years pandemics of our not-so friends of the genus Aeromonas (very likely)... Bleaching is about the best course in my opinion... though some folks like the formalin/formaldehyde route... and in the fisheries biz for real, we dump, lime/lye the bottoms of all basins... and leave the systems empty... for years.... 
Thanks for reminding me to finish posting the rest of my "maintenance" pieces on the www.wetwebmedia.com site for ponds...
Be chatting my friend,
Bob Fenner