The bottom has no horizontal support whatsoever? I was going to say that the top horizontal support would have me worried, but then I noticed the bottom tank...
Is there a gap between the bottom of the upper tank and the middle of top of the stand? Seems like with both tanks, the weight is being supported at the ends of the tanks only. That's a lot of pressure.

Is there a gap between the bottom of the upper tank and the middle of top of the stand? Seems like with both tanks, the weight is being supported at the ends of the tanks only. That's a lot of pressure.