That's a good idea; in fact, it's what I did last night, and it
cleared up the water immensely. Now I think I can take a fine net and
strain out any floating particles that are still clouding the water.
I know U. gibba flowers best in very shallow water, so I may drain
off a bit as well.
By the way, have you had any luck getting your U. pubescens to
flower? Mine is putting up four new scapes, and I think I may have
finally hit on the secret: raise the water level to just above the
soil surface. Apparently this is one species that likes it a little
wetter.