I like the wood. How long has it been in the tank? It looks like it's still leaching some tannin into the water. I would stick with the water changes to get rid of the yellow/brown tint, unless that's the look you're going for.
Here's my constructive criticism:
I think you don't have enough height in the tank, especially on the right side. I would get more driftwood, or a larger stone, to give that side of the tank some height. Second, the floor is a little distracting. I would try and nurture one species into more of a "carpet" and let the others grow tall in the back of the tank (behind the wood?) to give the aquascape some depth. Finally, leaving some bare sand as a focal point between the two "tall" sides of the aquascape gives the viewer's eyes a place to rest. You might be interested in the "Golden Ratio" of 1:1.6 to find where that focal point should be either left or right of center.
All in all, I like where it's headed. I especially like the detail in the wood, I think you've got a great piece there.