Hi Ted Aloha:)! Have you upgraded your tank now to 100 gallon? that was big,in 100 gallon tank,you will need a dimmable,if you will choose some 55x3 LED in 100g,you will need atleast 2 or 3 if you want more spread 3 is best. I am using now that 55x3 to my tank 29g,it is dimmable,with combination...