Well, first thing I must ask is, "why are you just now asking about how far the light should be?" You are that far into flowering, you should know by now. That's an odd question at this time...do a search if you REALLY need to know that answer. There are a boatload of threads on this subject.

2nd, yes, the 11/13 should be fine.




TGF

Edit: To save you some search time, just in case you ARE serious...do the hand test. move the lights until they are above the canopy and your hand can sit there at the ssame level for at least a minute or two and be "comfortable."
TheGreenFog Reviewed by TheGreenFog on . how close to the light? how close should my 600 watt light be from my lovely budding sativa? currently on 7th week of flowering, also would 11 hours light and 13 hours dark be better for last few weeks of flowering? Rating: 5