I'm loving the moss growing along the top of your driftwood. Looks really sharp.
I'm not sure if I was misreading a previous post, but are you doing liquid CO2 in some form? I've read that vals and liquid CO2 (like Excel) don't play well together.
I thought this would be a problem but I started dosing EasyCarbo (liquid CO2) and the vallis did melt a little bit but I just kept dosing as normal and it seems to have grown resistant to it. I only get the odd few leaves turning brown but they were probably on their way out anyway. If you continue at 1ml per 50 litres and don't put it too close to the vallis it should be fine. I've been doing this for over a year.