First, we laid the pieces down on the back of the tank to get a general idea of what fit where. BTW, the empty tank was laid down on its back in the livingroom while we worked on it.

Then, we picked up each piece of cork and place a dab of silicone on the contact points where the cork touched the glass and siliconed them in place. Next, we filled in the holes with black Great Stuff and covered it with dry peat while it was still curing. You can see some of the black spots that didn't get covered and I think that those were the places that we missed the first time around. We were careful not to put too much GS between the cork and the glass because of the expansion. Black Great Stuff is used for ponds and it's a little more expensive than the regular stuff, but the regular GS would work just fine.

I had planned on putting a vine in to start covering the background, but I think I'll leave it as is for now. I may add some small broms later on -

In the meantime, we're finishing the 20g today. The waterworks look super and I'll post pix when it's done.