Males will flower regardless of the light cycle, so I don't know that there's any really easy answer. But a box with a HEPA filter that you keep as far as is possible from the females might work, like opposite side of the house, on a different floor, with the filter, and behind a closed door. That should at the very least minimize the amount of pollen that gets to your females. If you try it, and it works, please let us know, as I'd like to do the same thing at some point.