I'll be adding a MH in this weekend, along with a few new plants that are ready to start flowering, so I'll keep you posted how those compare to ones without the MH in flowering. I'll be using clones from strains that are already in flower now, so it should be easy to see a difference if there is one. I log photos of each plant every few days, so I can post some comparison pics. It'll be a few weeks I suppose before anything could really be seen though.