turn off or not for winter

My filter is a veggie filter, water hyacinth, watercress and today I discovered
string algae.Plugged up the outlets to the waterfall and was backing out water
over the back (!!!).
Drained the filter, tossed the water hyacinth and string algae and shut down
the pump. That's it for winter. The watercress in the waterfall will just stay
there, suffer winter temps, no water, snow, ice and come back next year.
Amazing plant.
I'll put in an air pump this weekend in the pond to keep a hole open in the ice
when it comes.
Pond is 3,000 gallons, bunch of goldfish, four small koi and one elusive lady
bullfrog.


kathy :-)
zone 7, SE WA state