The new tank went in the same spot in the living room that the old one was. The new one sits about 18" lower than the old one, but when the basking area and the rest of the "upstairs" were finished, it would have been almost the same height. The basking area that we have now is a plexiglass 3 sided box with a ramp going up to it, and a roof. (Roof? Yeah, he tried to use it as a ladder and climb out, so we had a roof attached to prevent that.) It hangs on the end of the tank. It worked well when he was small, but now needs to be replaced. The
plan was to replace it with a 1' x 39" (The length of the new tank) area of grass added to the attached to the long side of the new tank. Obviously, that didn't happen.
Maybe I need to hunt for a larger glass/plexiglass tank rather than as dark tank? He just really seemed to hate the dark tank.

We'd tried to this once before and he did the same thing--ate way less than normal and hid. That attempt lasted 3 days and we gave up. This time, when he quit eating completely, well....I got scared and 2 days was enough.
Yertle has always been in glass and has always been the centre of attention in the house. (Tv and computer are always where he can see them, etc.) Maybe "Where'd everybody go?" came into play here?
Or am I just bein' an ol' worry wart? (I
do tend to do that...) Maybe I should have just let him tough it out and he'd adapt in his own time? Stress + not eating had me really scared, I guess.
Still I see no signs of anything wrong after the fall. Hooray!!
The algae problem seems to have stopped for now. Also hooray!
I really do appreciate these comments more than I can say--we're so new at this and so horribly ignorant and do adore Yertle. I really want to do the best I can for him. You've been a big help!