Seachem Flourish Excel is a source of bioavailable organic carbon. All plants require a source of carbon. This is typically obtained from CO2, but, may also be derived from simple organic compounds (such as photosynthetic intermediates).
Flourish Excel has substantial benefits when used alone or in conjunction with CO2 injection. The combination is particularly ideal for situations when continuing to add CO2 could result in dangerously low pH levels.
Flourish Excel also has iron reducing properties which promote the ferrous state of iron (Fe+2), which is more easily utilized by plants than ferric iron (Fe+3).