On Mon, 30 Mar 2009 19:39:09 EDT, "JB" wrote:

~jan,

I have a bio/mechanical filterfalls and do some water changes but not nearly
as frequent as I did years back with a smaller pond. I have 5 Koi, 3 that
I've had since 1998 and are about 24 inches long and weigh several pounds,
and around 25+ different types of goldfish in my 3,000 gallon pond. I turn
the water over once an hour through the filter.

If you're not too attached to the goldfish, you might want to get rid of
the majority of those, might help your spring greenies. Since I started
weekly water changes of 20+% my water quality has been amazing. I wish
though I could set up a flow thru system like many ponders have locally.
~ jan
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Zone 7a, SE Washington State
Ponds: www.jjspond.us