Hey so i just picked up 2 24" light fixtures which each hold an 18" bulb. I was going to use these to replace a homemade canopy with a shoplight built in. Each of these 18" aquarium lights have 15 watts, but the regular shop light has 60 watts. Which would be better for the low light plants (crypts, anacharis, hornwort, banna plant) that i already have in the tank?