If your basement has a concrete floor, it's a lot easier to do than a wood sub floor. just beef it up under and put your mind at ease. I used two adjustable floor joists and a 4 x4 under my 175g. I went for years without them, but I always freaked out with the kids went running by my tank. When we installed tile, I added more weight to the whole floor. So I installed them and I am the tank barely moves. This is a shot under my tank in the basement.
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