Quote Originally Posted by CFLMaxYeild101
...Under 336 wtts ,Thats 8 42 wtt cfl's pushing out 21600 LUMENS...
Sorry but you are not pushing 21600 lumens with 42W CFLS.

If you have all bulbs within a box 12" square, recessed with nice reflection parabolic backing you might hit some high lumen numbers. But you cannot add up all the lumens and think that is what you are putting out.

This isnt correct.

You can still only grow small tomatos with those lights...although small tomatos can be very good one indeed.

Just dont fool yourself with the lumens....they dont add up like we would like to think they would.

Best of luck on your tomato plants.