I have a 55 gallon aquarium that is 20 inches tall and a r-zilla comb fixture that takes a 48 inch t5 bulb. I noticed the r-zilla uvb desert t5 bulb and all the others i've find say effective up to 12 inches. I've seen ones effective up to 20 inches but they are not t5 and will not fit. I just bought the light fixture for 130 and really like the setup. Does anyone know of a 48 t5 that would be effective with that size tank? Thanks