Are those all the seiryu stones you bought? Or do you have extras that are not in the tank?
I think I would move the three larger stones to left and the two stones on the right, more to the right a bit. Then create a little bit of a slope on the right as well and even out the substrate in the middle to create a valley. Right now you have some substrate kind of gathered up in the front middle against the glass that's throwing me off a bit.
I like that you're using an odd number of stones.. so if the right side is only left with the two stones after some re-arranging, perhaps if you have some more seiryu you can add there as well.. like smaller ones.