Gold barbs...Cardinal Tetra and a Red tipped black shark?
Is that all in inhabitants?
I think the scape looks nice.
The shark will eventually become a bit too aggressive in 30gal for tankmates so I'd probably drop him.
And the gold barbs look a bit big compared to the tank, but if you like them then they are nice fish
What's up with the Alternantera reineckii in the middle back of the tank? Was part of it eaten away? Or did you dose with something? A. reineckii doesn't like Excel. At least that has been my experience. I'd clip the bottoms off and replant the tips with leaves towards the front of the tank.
I like the rocks. Is that algae on them. I don't dislike this.
llj
I agree with Geoff1991's comment, the right side seems to be too devoid of rocks. If you can move the rock the the right-center and see if the inclination of it will face the left side of the tank, that may look good.... but i am really looking for suggestions as to what plant to try in the center, what ground cover, maybe less or more rocks, adding driftwood..... anything you can think of!