So I was wondering how they take the weight? I have one tank that is 125 litres (33g) and its on the fluval 125 stand which i know is made for the tank. But with the weight of the water and tank when full how does it handle this? Because the stand has no central support at all? Its on support at the left and right side.
Yes the load (weight) is distributed to the sides and the 5 cross members that are visible in the picture share the job of keeping the stand square(lateral support). The bottom one and the one in the shade doing the brunt of that job. The top deck is to transfer the weight to the sides and the top illuminated cross member keeps it from sagging as does the large shaded cross member.