We're having a problem with a heavy stream of air bubbles pulsing out of the pool return when the solar is running. When this is happening, the pool sweep also will not run properly - not enough power. We've "fixed" the problem for now by simply turning the solar off. My question is, is this really a solar problem or a pump issue? We've checked all the valves, o-rings, etc. for leaks...nothing. Any help? Thanks in advance.