T5HO bulbs offer 3 power levels, (24W, 39W & 54W) & are the perfect bulb to use with any GLO T5HO lighting system. T5HO fluorescent bulb technology delivers significantly more light output per area of bulb surface versus conventional fluorescent bulbs. T5HO technology offers big light potential when considering that two T5HO fluorescent bulbs can be installed in Approx. thesame space as one T8 or T10. Aquarists with heavily planted aquariums employing CO2 injection as well as many marine reef keepers now have an efficient, affordable alternative to other high intensity forms of lighting. When considering the depth of most standard aquariums, T5HO fluorescent is the ultimate alternative in high light output performance in a linear fluorescent format. GLO T5HO offers advantages over other high output lighting, such as; relatively lowheat production, even light distribution, comparable or superior spectral longevity & energy efficiency.