The heater is now next to the filter on the side of the tank and i've added a background. All i did was get some coloured paper (pale blue) and tape them together and tape all over them to make them 'waterproof'. It doesn't look too bad but it's only temporary.
Green grass will go, it was just either in the tank or in a draw, so i put it in the tank.
It's looking great, but as everyone else had said, it could definitly use a lot more rock and I would suggest a solid black background. Once you get more rocks, I would add some plants...only a few to give some color to the tank, but the grass doesn't look to great. I also love the labs. Your tank is looking great, I can't wait to see it when it is finished!