Originally Posted by jschristian44
my light is fine. i am sure its nutrients as well. i got excel flourish because on amazon site it said that it is the same thing c02 provides and i thought thats what makes them green. i dont want to have to get another thing that doesnt work.
This is rather more complicated, if I may explain. Plants "grow" by photosynthesizing, and photosynthesis causes the lush green appearance of leaves. Plants will only photosynthesize if all required nutrients (17 of them) are available and the light is sufficient--which means intensity, spectrum and duration--to balance. When any single nutrient, such as carbon (via CO2 or Excel), is increased, growth/health is unlikely to improve unless that particular nutrient was totally missing previously.
As there is quite a lot of natural CO2 occurring in most tanks with fish (and more CO2 comes from the bacteria in the substrate anyway), it is the other nutrients that are more likely to be missing or in short supply. A comprehensive fertilizer like Flourish Comprehensive will usually be sufficient to provide everything (aside from CO2, oxygen and hydrogen which naturally occur). If there is a balance existing, adding more CO2 will only have value if the other nutrients are already there in excess, and the light is increased again to balance.
If you stop the Excel and add Flourish, I would expect your plants to improve. Swords are heavy feeders, and Flourish twice a week instead of once is often necessary.