Are you using 2 vhos on 1 workhorse 7 and plugging them in serie?
apparently workhorse 7 can only run one vho bulb
and if u plug them in series they will be overdriven by 20%. and they dont recommend that.
check this out
http://www.aquariumpros.ca/forums/sh...highlight=fire
http://www.aquariumpros.ca/forums/sh...5&pagenumber=1