I am currently doing a 720G tank out of acrylic, and after buffing and sanding this beast, I would hate for my 3 year old son to scratch the outside up, so I researched and found that ETR rebuffs public aquariums, and basically puts clear window tint on the front of public tanks to be removed and replaced each year to keep the outside acrylic as good as new.
With little kids, might be something you want to look into.
Mark
PS - can you post a link to the museum, as it might be a place to come and see this coming summer.