Hello all. It's a pleasure to be here on this site. I've been a member for over 5 years just fascinated with everything that I've seen on this site. I figure that it's time to get into the thick of things but first I have a question about my aquarium glass thickness. I've seen a lot of builds on here with different glass sizes and thickness. So here it is. I'm going to be building a plywood aquarium as I built one before. Just not this large. The tank will be just under 400 gallons. The question is that I need to know if this glass that I'm using is safe? I have the background on the glass and all. It's 6' long by 4' tall. I have several pieces of it as it was originally an aquarium. The guys that I got it from broke the tank down and I decided to get the glass from him. The inner dimensions of the tank is 74 1/2" (L) x 39 1/4 " (H) x 29 3/4" (W). Again this was already a tank at one point so I figure that it would be okay to make a few tanks out of the glass. The glass is 1/2" thick as I've seen a guy on here do a 500 gallon with 1/2" thick glass. I want to know if this glass will be okay with the dimensions given and if so I will post every pic of the build. It's just that I've been getting conflicting answers about the thickness that should be used. It took too long but I've here because I trust this site the most. I'm so ready to get started with this project. Thanks in advance for any advice available.