Thanks everyone. I did decide to use the sand but only a shallow layer.
Merlin got the new tank yesterday.
My dad has had an 80 gallon tank sitting him his living room for years, empty and dirty. He offered it to us a while back but at that time we didn't have Merlin so we declined him offer. Now that we have Merlin we asked if the offer still stood. It did!
Yesterday my dad dropped it off and I set to work trying to clean it up.

I had some help taking the water out of the old tank.

Here is the new tank now:


Merlin seems to like it, though he didn't like sitting him his little container waiting for me to set it up.

I think he approves.
