I am planning to build and acrylic sump for my 300 gallon DT I was planning on a 125 gallon sump. I also want to make a frag and possible QT tank if I have enough acrylic left. Are their guidelines somewhere on how thick I need to buy for x wall height? Or is it the total amount of gallons? Both of these tanks will be pretty low..less then 20" tops but I'd love to be able to build bigger tanks if this works out. At what point do I need to add bracing? When is a full sheet brace called for or is euro style with an open center doable? I'd love to hear from some experienced folks.