thanks ross, and thanks again for all your help threwout this build.... i forgot to explain but when it comes time to finish this tank off im going to build a "fake" wall infront and on the side by the stairs so it will still look like its an in-wall tank this is the reason for leaving the little bit of room behind it so i can climb back there and do any work i need to do. i will stuff insulation everywhere i can fit it behind the tank and surround the sump. inside the "tank room" i will have either 2 6foot t5 ballists that hold 4 bulbs or 3, 4foot ballists that hold 4 bulbs and it will light both the tank and be enough light to grow the plants in the sump