My brother noticed a steady stream of bubbles coming out of the holes in the sides of the pool where the solar system water normally enters the pool (there's probably a technical term for them but I don't know it) and told me it looked like there was air in my pool system. As he is younger than me I hate it when he's right, but since he has more experience with pools I figured I'd take his word for it (don't tell him I said so). When I turned off the solar system the bubbles stopped so that does seem to point to the solar heater, doesn't it? Any ideas?