correct me if im wrong but shouldnt the tank be touching the stand all the way around?
in the last picture looks like tank isnt touching in the middle area!!
if it was me id get something under it
i learned the hard way with a cracked tank and 50 gallons on the floor
as long as the ends are well supported glass tanks do not need to touch all the way around. gaps in the middle are fine provided the tank is flat and level and the ends are well supported, which in this case they appear to be.
not so for acrylic tanks though. they need full bottom support.