I have around 6k and 3 1/2 foot deep pond. Should I allow the waterfall to run all winter? im in ny and it will freeze but my waterfall/boifall is big and likely won't freeze provided we don't have any loss of power. i do have a large aerator to keep the surface in multiple spots from freezing. all of a sudden i have some long algae attached to everything. will this die or must i remove it? thanks in advance.