Man that sucks. I don't even know what to say about that. I've had my hot rod vandalized a few times in my neighborhood, and it just makes my blood boil. Something like that doesn't really seem random though, breaking the front pane on a plywood tank would require some serious effort - whoever it was would have to enter your closed garage, hoping nobody was home, find osmething big and heavy enough to smash the glass with (or have it with them already), smash it and avoid getting cut or injured, then make their escape after making all that noise and flooding.
You were thinking about putting a webcam on your big tank anyway, maybe surveillance is a good idea for more reasons than one.
You were thinking about putting a webcam on your big tank anyway, maybe surveillance is a good idea for more reasons than one.