maybe instead of steel frame all around.. maybe just some angle steel mounted to the inside of that Dado. I understand the 3/4 ply attachment, but I think in reality that may be compromising the joint more as you are driving screws into the grain.. thus providinga good place for the grain to split.
it just that I have seen arrangements like this fail before, not in an aquarium, but you have the entire stress of the front panel on a 1" by 2.5" piece of wood. two pieces of angle steel would cost next to nothing.
ahhh. I think I understand, so.you have screws oriented parallel to the glass.... essentially securing the edge of the Dado to the rest of the post.. or am I getting it wrong?.
Yes I understand what you are getting at. and yes the screws are parallel to the glass so hopefully they would help support the wood in case of anything.