Critique my rack layout. Does it look stable?

[saint_abyssal]

I'm tentatively planning a rack of aquaria laid out as in this diagram using a 60 in. W x 72 in. H x 18 in. D Gladiator shelving unit from Home Depot. Obviously, I don't want this toppling over, so I'm worried about stability.

My biggest concern is that the layout is a bit top-heavy, since most of its total weight is in its upper half (above the dotted line).

My second biggest concern is that the weight distribution is asymmetrical: side to side on the top row, but also front to back as I planned for 2.5ers where there was room for them behind the 10s and 16 talls.

At reddit someone recommended that I anchor it to the wall. Is that absolutely necessary? I live with my dad and he's not very supportive of my interest in fishkeeping. He definitely wouldn't like me doing things to the wall. Is there any way I could safely get around that?

 

[Andy Sager]

It's all going to depend on the stability of the stand and the levelness of the floor. The heavy weight on the bottom on the stand SHOULD keep the lighter tanks above from causing any issues but if the stand is free standing in the middle of the room, there is always a possibility of toppling it if you lean too hard on the stand.
One thing you can do is build a larger wider wooden platform to place the stand on then using L shaped brackets, attach the stand to the platform on all 4 legs so that you can't push the rack over when working on it. You can also attach 2x4 pieces at the top of the rack so that they rest at the wall ( use some cloth or felt or something to keep from scratching the wall) so that the top can't sway. These are all preventatives because when you use things not designed for holding fish tanks, anything is possible to happen. Fish tank stands are designed not to have these issues.

Hope this helps.