Grayum

Hey guys, just got a 4x2x2, I set it up as an NPT. I have a quick question for anyone that has had a tank this size. Should I be worried about the floor?

I put the tank in a position where the beams will be running long-ways not laterialy under the tank, so I assume that will help. Is it normal for the water to move a bit when i walk past it? I used a level to make sure nothing was sagging and it seems it leans SLIGHTLY forward, probably 3-5 mm. all together. I am not worried about the actual tank or stand, as the person before had about 100- 150 pounds of rock in it as well. Please, if anyone has experience with this please let me know as I am actually losing sleep about this. Thanks in advance.