From what I'm interpretting you are planning to have the 1st tank on the floor? I'm not sure how you will suspend a both tanks on cinderblocks. That aside, I'm concerned with a few things here.
1. Placing Just 2x4's under a piece of glass could lead to problems as there is a natrual arch/bend in this type of wood and that could bend the tank.
- Consider getting some 1" foam insulation to put between the 2x4's and the glass this, in my experience, will deal with this problem
2. I don't see a lot of thoughts to keep the tank from "swaying". You are going to have at least 1200lbs of water and glass sitting on a couple of 2x4's that, from my interpretation will not be anchored to the cinderblocks. I would worry about the tank if someone fell, tripped, bumped heaviliy into it.
- Without additional information I can't really say I like this for stacking tanks. just an opinion mind you.
It's very possible that there is simply not enough information here yet. I don't want to seem like i'm bashing your idea either just some observations to be considered
1. Placing Just 2x4's under a piece of glass could lead to problems as there is a natrual arch/bend in this type of wood and that could bend the tank.
- Consider getting some 1" foam insulation to put between the 2x4's and the glass this, in my experience, will deal with this problem
2. I don't see a lot of thoughts to keep the tank from "swaying". You are going to have at least 1200lbs of water and glass sitting on a couple of 2x4's that, from my interpretation will not be anchored to the cinderblocks. I would worry about the tank if someone fell, tripped, bumped heaviliy into it.
- Without additional information I can't really say I like this for stacking tanks. just an opinion mind you.
It's very possible that there is simply not enough information here yet. I don't want to seem like i'm bashing your idea either just some observations to be considered