hi I bought 2 of this uvb controller, Hagen Glo Light Controller 30W pic included, is it ok using a Zoo Med ReptiSun 10.0 18W 24 in or does it have to be a 30w I only ask because I bought 2 brand new Zoo Med ReptiSun 10.0 18W 24 in and noticed a slight blacking at each end, this has happened with both new uvb controllers,