im guessing its the table ,if the floor can not support a 36
gal tank that building has a major problem and should be inspected by an engineer
that tank weighs less per square foot than a person , or appliances
1/8" off should not effect it mich mine is more than that
one way to get the floor to support the weight better is to put a piece of plywood under the stand to spread the weight load over more floor beams
ps tables are not designed to hold 300 lb which is about what a 36
gal tank weighs