110 sounds about right for a 4''lamp but you may have to get the 46.5'' lamps#ed_op#BR#ed_cl#for it the 4' or just a tad long for a 4' tank#ed_op#BR#ed_cl##ed_op#BR#ed_cl#And I'm with Dave on PC onle i don't get 9 months more like 6#ed_op#BR#ed_cl##ed_op#BR#ed_cl#But then i change out my MH after 10 months some say a year but i like to be on the safe side#ed_op#DIV#ed_cl##ed_op#/DIV#ed_cl#