If the house is single story with concrete slab construction no problem. If it has crawl space underneath or the tank is going upstairs find someone who knows about the weight bearing loads of the floors and the direction the support stringers run. A 120 will weigh in filled at over 1100 pounds. If you are moving the 75 over too it can make the switch easier and not seemed rushed. I just recently went from a 55 to a 110. I took my time to paint the back glass, research the substrate and wash it. Find lights I wanted for a good price and an easy cheap mounting system for the wood canopy. And then up graded the heaters. The biggest problem I had was the 110 was to go into the same location that the 55 was in. On the day of the move I used one of my extra canister filters to pump out most of the water from the 55 into a very large cooler that had never had any chemicals in it. My neighbor came over to assist moving the 55 a few feet to another wall with fish and plants still in it. I started refilling that tank with the filter from the cooler, while that was going on we set the stand up and mounted the 110 on the stand. That took about 30 minutes of his time. Added the pre-washed substrate, added SeaChem Prime, and filled with water. I then plugged in my extra filter, the next day plants, fish, and the other large canister pump where added from the 55. The canister filter on the 55 was rated for a 100 gallon system.