I just read the new catalog and checked out the new products at the GH website... Here is some pasted info about the two nutrient lines you are interested in:
Flora Series is Flora Grow, Flora Micro, and Flora Bloom.. It is three-part mineral fertilizer.
FloraDuo is a proprietary complete nutrient
system, especially designed for fast growing
plants, with a marked difference between
growth and flowering needs. It comes in 2 parts:
FloraDuo A and FloraDuo B. FloraDuo is not
as flexible as the Flora Series however it still
provides you with the ability to adjust the nutrient
profile to meet your plants needs at every stage
of growth from cutting through harvest. Duo is a
cost effective, user-friendly easy to use concentrated complete nutrient system.
Designed to work in Coco, Hydroponics,
Soilless and Soil.
We recommend using CALiMAGic, Floralicious Plus and
Liquid Koolbloom with FloraDuo for additional flavor