Quote Originally Posted by caferacermike
It is generally not a problem. You should consider adding piers directly under where the tank will sit. I have a 125g tank in a house that was built in 1918. The floor is about 4' above grade. Before setting up the tank I laid a few patio blocks on the ground, screwed a few 4x4's in a mock perimeter of the tank to the beams, and added screwjacks between the patio blocks and 4x4's. I also have an unbraced 75g as well. I have extra jacks if you decide you need them.
Agreed, if you have a friend that welds, maybe they can help reinforce the floor right there. I imagine that there would be steel support beams on a manufactured home. Our friends did 100+g in a pier and beam, but they made sure to reinforce first. Better safe than sorry!