plants will not stretch unless you go below 1500 lumens. but with that you get minimal growth.
closer the lamp, the bigger the buds and leaves, but more heatproblems.
say a 150w hps, 3-4 inches aways and you have 16000 lumens on the plant, but you also have to have more fans and now you only cover 1sqf.
1 foot aways and you have 8000 lumens per sqf and now you have 2 sqf coverage. but a lot less heat to deal with too.
7500 lumens is considered optimum, but i dont know i currently have about 30000+ on 2 square feet *each, with quite a bit more in the center id think, 2x150w hps + 4x 49w t5*
*spacerestrictions and im also curious* and the plants dont seem any worse off *only been 2 days of that so well see, i have 1 plant in 17000 lumens *t5* and 1 plant in 21000 lumens *70whps + same t5* * |