When I had my tank out I had ordered what I thought was the bottom seal but it was incorrect so I think I ordered another like yours and it was too loose sitting on the floor so I ended up using a sponge rubber hockey puck and drilled a hole in the center .I don’t know if it was because I had put some rubber on the saddle were the tank sits and that made it sit a little higher but I think it was no more than a 1/8 thickness .
