Thanks Roger
Im not sure that I have things set up correctly.
I have one power head on one end and the other on the opposite end of the tank.
The inverse mode - my master controller is solid red on the pulse led, while my slave, if I put it in non external mode, flashes red on the pulse led. Is this correct?
Do the flashing of the buttons on the controller represent operation - in inverse mode should the flash alternately? or at the same time?
Also, does the feed button work in external mode?
Thanks again for your time!