Easy to make the wood version on the 20 gallon.
The glass method is a bit more involved but not that hard even if you do not remove the rim from the tank and add glass slats(you can still glue the glass to the plastic rim etc).
Open tops are sooooo much easier to work on.
The tank is a biotope(Florida) and there will be some Alligator Gar in there when the tank is finally completed and grown in well.
Then I'll rip it up and do another totally different biotope of Florida.
As a matter of fact, all my tanks including my SW are biotope tanks.
Regards,
Tom Barr