Unsinkable!

[aqua786]

You should really take the bark off as it will just rot eventually.

My trick was to take an interesting and large rock and just pin the wood down with it (the rock right of center):

I must say,your tank is beautifully made up,well done! what is the plant at the centre of the tank,the one with the roundish leaves whic looks like its hanging? is it creepig jenny by any chance?

 

[This Old Spouse]

Thank you!

It's called Brazilian pennywort (Hydrocotyle leucocephala)and grows like crazy. In this photo it had just become uprooted because of my new filter, but the best look for it is to plant it and let it grow to the top, then it will grow along the water surface.