Did u attach it above water? and would it still float or has it become waterlogged?hi looks great man,
instead of hanging your plants from the top of the tank, you could just hang the piece of driftwood from the wooden supports,
i've done the same on my 220 gallon and it can look really natural for the amazon look you want.
heres a pic of my 5ft piece of hawthorn trunk hanging from the top, i could lie and say i planned it this way, i didnt , it floated when i first put it in and i ended up attaching it to the top as it looked far better.