i used to run opposite for a few months then switched to 24/7. with the 24/7 i've noticed a lot more growth as well as slightly lower nitrates. with it was on opposite, it didnt grow at all. im going to start running it about 22 hours a day so it has a little down time as all living creatures need. i have also noticed more nuisance algae in the fuge as well, but thats alright since all algae is eating up extra nutrients. with all this on 24/7 i have noticed a decrease in nuisance algae in the display tank as well. all in all, it seems as its actually doing what its suppose to now that its on 22-24 hours a day verses 12 hours a day.