The fact that you had to make a thread about this shows me you had serious doubts in the first place so in a way you already knew the answer to your own post before you even submitted it to the forum.
You've made the right decision in the end, personally there's not a cat in hells chance i'd trust them shelves, they just simply have not been designed to hold a continuous amount of dead weight such as a filled aquarium. I don't care what the manufacturers say their safe weight limit is. A solid wood stand all the way, or a custom made proper steel stand. Peace of mind innit.
You've made the right decision in the end, personally there's not a cat in hells chance i'd trust them shelves, they just simply have not been designed to hold a continuous amount of dead weight such as a filled aquarium. I don't care what the manufacturers say their safe weight limit is. A solid wood stand all the way, or a custom made proper steel stand. Peace of mind innit.