Thanks all for the input. To put some minds at rest, before constructing I consulted with a local who has over 25 years in the plastics fabricating industry. (he owns a fabricating business). I also consulted with a state licensed engineer. (not some 4 year degree type, an actual mechanical engineer).
I like the comment that "anybody with a table saw and a router thinks they can build a tank". The short of it is they can. Tank building is not nuclear science, its not rocket science either. I firmly believe that someone with the right tools and some good quality input/advice can design and build anything they want. I don't have 10-25 years experience in tank building, only about 4 years. This makes my 4th tank, and about 8-9 counting sumps I've built. I am always interested in learning more ways to do things, but I don't feel that destructive criticism is beneficial.
I have found that in every crowd there is always a few nay-sayers. These types were the ones that cried the world is shutting down on Y2K, what a joke.
As to the comment about not putting anything other than air in the tank, well to late. If you really have over ten years experience in plastics assembly, then you should know better than saying that. There are many tank manufactures out there that use as light or even lighter material for tanks. Tenacor on their 300 gallon (96x24x30 tall) use only 1/2". I have seen this and it has a "belly" on it. I am personally not very comfortable with this. To me it seems that the more you static load the walls of the tank, the lower impact it will take to fracture it. I also looked at some tanks in the Seattle area last weekend that were selling as 150 gallon with only 3/8 fronts. (48x24x24)
Making a statement like "leave the tank building to the experts", I say give it up. Had I talked to you and you sounded like that I would have laughed. A real professional just states the facts, they try to leave the hype out of it.
I will install this tank in my house, not anyone else. It is a fact that my insurance covers this, not yours. As to putting people in the hospital or even possibly killing small children, just drop it. That's just hype and emotion taking over. I don't plan on in-roaching on some ones business line, I am just saving a few thousands of dollars.
Sincerely,
Les Peterson
Kennewick Washington