I read somewhere that 6 t5ho's 3 10k's and 3 actinics, are equivalent to a 400w mh. That maybe be wrong as I can't determine where I got the quote from, but I know my 78watts of t5ho kills almost 200watts of power compact lighting. and the pc lights cost twice as much and have to be replaced every 6-8 months. t5 are only replaced every 14 months.