I’m new to this hobby and I received a 40 gallon breeder tank for Christmas. My son is selling me his Reef LED 50 live for $75 and a universal mounting arm to go with it. The mounting arm isn’t fitting on the breeder tank because of the rim around the tank. I’m wondering if there’s a better mounting arm out there that will fit. I’ve looked online and I can’t seem to find one. Does anybody have any ideas for me? Thanks.