I use Flourish Excel for carbon and Flourish tabs (which I think is the solidified form of liquid Flourish? ), and my plants are doing quite nicely. The crypts have stopped melting, no yellowed leaves, and new growth is showing up. :thm:
You will need nitrates (of which you may have plenty due to bacteriological digestion of nitrites), potassium and phosphate as well as carbon. Please refer to http://www.seachem.com/support/PlantDosingChart.html
Having said that I was able to create a nice looking planted tank with only Flourish and occasionally Flourish Excel.
Also dosing individual ferts is not that bad. I mix up a 2 liter soda pop bottle with the appropriate dosages and this bottle will last a month. Please refer to http://www.rexgrigg.com/index.html
I use both in all of my planted tanks and my plants are doing well and showing some really nice growth. The best part is the algae that was in these tanks is practically non-exsistent.
I've seen some people report problems with shrimp and Excel, but others have started with half-doses and had no problem. I guess the shrimp acclimate to it.