I also run my fuge on a reverse photoperiod...but, what is different in my fuge than most folks is that i have an enormous amount of xenia growing like weeds.....oh yeah..i have some chaeto in there too!
I run the fuge lights for 16 hours, but it gets a lot of light indirectly b/c it's close to my windows...so it prolly only gets close to 4 or 5 hours of total darkness
the growth rate of the xenia is explosive, to say the least....but the chaeto growth rate could be improved a bit...i'm only reaping chaeto every 2 weeks or so.... ideally, growth should be so much that weekly harvesting is required
Zach