I just got the reply from Fox Farms.

I was told that Big Bloom doesn't have enough phosphorus in it to use as a stand alone fertilizer when your plant is flowering. Also, the Tiger Bloom and the Grow Big both have your necessary micro's.

You can use Big Bloom in combination with Tiger Bloom. (already knew that according to their schedule)

Big Bloom can be thought of as a catalyst. Big Bloom can be used the entire plants cycle, on new plants, and on plants that are not doing well.

Handy info, hope it helps. :jointsmile:
Rusty Trichome Reviewed by Rusty Trichome on . Yellowing leaves. This starts to happen after about two weeks in flowering, see pic. I started using only RO water (thinking nutrient lockout) and minimum dosage of Tiger Bloom (2tsp/gal). The leave on the left is from 2 wk flowering and the other is from an older almost done plant. I still get decent buds, but something isn't right. Can anybody identify problem by looking at leaves. The room is not hot 75-85, and i only use dilute nutrients. Peters 20-20-20 during veg (about 1/4tsp/gal). Thanks Rating: 5