I've zoomed in on your unit and as far as I can work out there are four extremely critical fail points. And because of these fail points you DO NOT want to be putting an aquarium on top.....as it is. But, if you love that unit that much that you definitely want to use it then there is a fix whereby you can put your tank on there and have peace of mind. Let me explain, my crude diagrams will explain better.
The first drawing shows why you just can't take the risk the way it is. The four critical potential fail points are where i've encircled "BAD". Obviously two at the front and two at the back. This goes against everything that a basic aquarium stand should incorporate in the design, and why have they done it this way?.....because it's not designed for extremely heavy weights, simple as. Simply put, your planned aquarium will be supported by the three middle very thin boards, NOT by the outer thicker boards. Even if you spanned the whole unit, which would be better, sort of, I still don't think i'd trust it long term.
The second drawing, if your DIY skills are pretty good, is what i'd do to "fix" the issue. Put a simple 2"x4" frame around it and wrap in with ply. Paint/stain it and it'll look great....and do the job.
I apologise for my crude drawing skills but i'm sure you see the flaw with the original unit and hopefully my second drawing gives you an idea of how to improve it.


The first drawing shows why you just can't take the risk the way it is. The four critical potential fail points are where i've encircled "BAD". Obviously two at the front and two at the back. This goes against everything that a basic aquarium stand should incorporate in the design, and why have they done it this way?.....because it's not designed for extremely heavy weights, simple as. Simply put, your planned aquarium will be supported by the three middle very thin boards, NOT by the outer thicker boards. Even if you spanned the whole unit, which would be better, sort of, I still don't think i'd trust it long term.
The second drawing, if your DIY skills are pretty good, is what i'd do to "fix" the issue. Put a simple 2"x4" frame around it and wrap in with ply. Paint/stain it and it'll look great....and do the job.
I apologise for my crude drawing skills but i'm sure you see the flaw with the original unit and hopefully my second drawing gives you an idea of how to improve it.

