Originally Posted by sewcrafty

What about doing a long rectangular piece that goes from the front of the chair and up the back and then add on the length you need for the tank and double that so you could bring it back up to the top of the chair and then sew the channel for the tank to sit in. ? I don't think the tank would take up the whole back piece, so you might even be able to make a couple of pockets to store some stuff in.

Can you visualize what I'm talking about?