I've had ponds for 15 yrs. and have had problems if I didn't use salt. I'mnot
sure what part of the country you live in, but here in the Mid-Atlanticour
winters aren't usually that cold. Milder winters increase the risk ofdisease
in your fish. Correct salt levels control bacteria, fungus, and
parasites that have over-wintered,also if nitrite is present, salt
willreduce the nitrite toxicity. Sooo, if your fish are lethargic and
losingcolor, it's a good chance you may need salt!

I am in the Atlanta area.....My ponds have a very low stocking rate, and lots
of plants. I avoid all chemicals, and most things un natural. My only
filtration is done with veggie filters, and I feed but not too much and use
proper food for the koi and goldfish .I use no uv and the water is clear enough
to see a small stone in 3 1/2 feet of water. the fish range in size from last
years babies to a few koi over 30 inches and all between....All in all real
healthy. Jerri

http://www.fringeweb.com/Ponds/JerrisPond