Thanks for the comments guys, unforntuately the 41 is now in a bit of a state as I had to transfer my Moonlight Gourami across to it from the 48 as the Keyholes had given it a bit of a beating. The Gourami has since decided to rearrange it's new home by pulling all the Cardamine up on the right hand side, and is now attempting to strip the Polysperma of it's leaves