The use of either CO2 injection or Flourish Excel does not necessarilynegate the use of the other. Because the processes of producingphotosynthetic intermediates and building onto them occur simultaneously,one can derive a substantial benefit with the use of Flourish Excel eitheralone or in conjunction with CO2 . The combination is particularly idealfor situations when continuing to add CO2 could result in dangerously lowpH levels. Flourish Excel also has iron reducing properties which promotethe ferrous state of iron (Fe+2), which is more easily utilized by plantsthan ferric iron (Fe+3)