In my 30g low tech planted tank, I had been dosing Excel for a number of months but I was just not impressed at all with the results. The plants seemed to just be limping along. So last week I decided to add two airstones to what I thought was already good circulation (Aquaclear 50 hob and internal power filter rated for 50 gallon tank). Well one week later, the gsa that was on my front glass is gone, two of my anubias are flowering, my miniature anubias are both sprouting new leaves, my one stalk of ludwigia that I haven't managed to kill off yet is roughly double it's original height, and my echnodorus ocelot sword is sending up a flower stalk. So there you go.