I love stamd builds,but i noticed your vertical 2x4's are toe nailed to the base 2x4..IMHO I would not feel safe about it, I would add a 2x4 that goes straight to floor and tie them all together...keep pics comin..
tagging along for this one. Your build is similar to one I have planed out. I'm going 36x36x24. Something about that cube-like size really makes for appealing aquascape possibilities.