I did a PWC on Saturday, and I filled the water all the way to the plastic brace at the top. I like to fill my tank so that the water flow from my AC110 makes as little bubbles/noise as possible, which means the water is well over the lip of the filter. Today (Monday), the water is already almost below the lip, which resulted in water trickling noise and a lot of microbubbles. I am very picky about this. Why am I losing so much water in so little time? I have glass tops. Could it be because I don't have the plastic pieces to connect to the glass at the back of the tank? The whole back portion of the tank is open, but only large enough so as to allow the AC110 to fit.