Stimulator Bloom Booster Advanced Nutrients® Overdrive® (250ml)

This product sounds almost too good to be true how long does a 3 oz bottle last & how much do you use at a time? need to know before I order, Thank yo

Can this be used with fox farm products? also does fox farm make a wieght gainer? besides tiger bloom?

So is this like a flushing agent of sorts, ment to use tikl the end of grow?

When during flower do i apply this?