Seachem Flourish Excel Bioavailable CarbonCARBON PRODUCTION: All plants require a source of carbon, and Flourish Excel is a great and convenient source of bioavailable organic carbon. IRON PRODUCTION: Flourish Excel also possesses iron reducing properties, thus promoting the ferrous state of iron (Fe+2), which is more easily utilized by plants than ferric iron (Fe+3). PHOTOSYNTHESIS: Plants must produce longer chain carbon compounds (photosynthetic intermediates). By dosing with Flourish