These last 3 comments really focus on what I'm thinking about.
Like I said, a certain range of plants seem to be doing well under my current set-up, and algae is at a minimum.
But, my tank sure isn't the alka-seltzer factor some of you guys have, and the growth - while robust - is not off the charts across the boards.
So, I find myself thinking, even though things are growing well under the current set-up, would they do even better with a little more/less CO2, higher or lower PO4 or NO3 - or a different ration between the 2, or a different photoperiod?
But the big fear is, as momo says, if I change something, things will get worse and I'll have a heck of a time getting back to where I am now.