Ed Rosenthal years ago was saying that 75 watts/ft2 was point of declining rate of return. I saw that in person in 04. This was mag ballast w/glass.
I ran 80 watts/ft2, 1/2 mh 1/2 hps, encased in reflectix this last run. Would have rather done like sixtysomething watts/ft2. Given the lack of glass, digi ballasts, pimp lamps, all that stuff, I might advocate sixtysomething watts/ft2 still. Crosslighting will make up for things also.
Definite correlation between light intensity and bud density. Shorter ripening time also compared to lower watts/ft2. Also "lowers", given sufficient intensity, will not be "lowers" per se anymore.
Reflectix tiled across surface of medium gave my lowers a fuckton of weight and frost I did not get before. But then airflow and cooling must be managed a little more cautiously by checking leaf surface temps.
I got one of those cheapass $50 hydrofarm light meters, dude that thing is awesome for $50.
I think max light intensity at top of canopy should be around 5000 footcandles or lumens or whatever(outside on bright spring day was 10,000 on the dot)
Have heard in a few places that max processing ability of plant occurs @ 5500 footcandles, that sounds pretty accurate.
Then again Greenthumbdanny was talking about 100 watts/ft2 w/magnums over tables, like 3 per 4x8, but his shit is overflowing past the borders of the tables a bit, and he was getting crosslit from other tables in room I think. Can't remember much more than that.
Checking w/light meter is best I think.
I would personally shoot for sixtysomething watts/ft2 if I were in your shoes at first, given digi ballasts dialed all the way up and no glass.
BTW I have fucked w/green party bulbs and green led headlamps, some plants get pissed off at that. Would not do that with any plants w/intersex tendencies under stress myself after my experiences. Maybe good for emergencies only.
Are you funded for good night vision? Passive of course, don't want an IR flashlight shining on your plants at night.
Staying busy it looks like, very nice work. Thanks for the shout out.
If I were in your shoes I might first try 4x4 spacing for the magnums, and a reflective curtain if necessary so you don't light empty floor space in the room. Buuut I have not worked with these reflectors, they throw hella wide compared to my super sun 2s.