I'm building a new tank to but it's around 100gallons so can you make that the limit for the contest?
When will the madness end, you can't adjust the rules of the contest so one contender gets to use something he already has. If it works out great, if not get over it.
I've never seen a 33 gallon nano, it's a 3 foot tank and people put tangs in them, since when do you keep such fish in a nano? If you make the volume range too big the unlimited livestock becomes somewhat of a joke. I think the smaller volume of total 20gal or less is key to making this work.