I really appreciate both of your advice. Lee, your pond is 3 years old?
Mine is 2 years old last week, and I remember reading many of your posts for
advice as I was starting - you were such a useful font of info 2 years ago
for me!

The SA problem lies in the edges where it tangles in the parrot feather or
water cress (both just wedged into rocks under the water, no soil) and also
in the WH roots, so I can't really harvest all of it out w/o ripping apart
other plant roots. So, I guess I'll just keep doing the water changes and
think about a rainwater collector for next year.