I do along with several other tanks.The 180 is on part of the floor where the span of the floor joices are only spanig 8ft though and also next to a support wall.For added safty the stand sits on top of 3 x2 timbers running at 90 degrees to the floor joices.The tank still sits just as level as the day I filled it up.My floor joices are 6" x 2" hardwood at roughly 16" spacings.I have friend who was worried about doing the same so he made a solid steel frame to go under his stand out of 4" i beam.
Just do some thorough inspections of your floor first.Stay near a support wall and choose a section that has the smallest span.