So this is my 2nd grow with that sf led and I just chopped my WW @ 55 days...which has a 70/90 day flower suggestion...can't say it was the light but I really don't know what else...and I go  past 1st signs cause that is considered pre flower...maybe 5 to 7 days past 1st signs...but not complaining got a bc grapefruit x zamnesia grapefruit x c99 almost ready for flower...oh and I don't think heat will shortin flower time...mine didn't get out of the 70s....