i can grow with all red ?? 240 watt .. tell me the...

A lot of the commercial blurple lights are a 65+% Red for bloom and 30-40% for veg phase. 👽 It depends on the plant, but the general consensus is blue is for veg and red produces denser buds, but you need to have a mix good mix to allow the plant to absorb light from all over the light spectrum. So there is no real answer, it depends on your grow environment, light quality, strain, and nutrients. During a long photoperiod, a low Red - Blue ratio is preferable to make more developed long cuttings. During a short photoperiod a high proportion of blue light will improve the medicinal value of cannabis in terms of cannabinoid content. Great article!- Reference: https://www.karger.com/Article/Pdf/489030 Good luck and happy growing! 💪💪