Yep. My 90g river tank is done after about 3 years in use. It never leaked, but I noticed some crazing in one of the corners, then I looked closer and the whole side gave away from the perimeter bracing. The cause of the failure was probably warpage. I used 1/4" continuos cast acrylic instead of cell cast acrylic to build this tank because that was all I could get my hands on at the time. I guess the key to building acrylic tanks is to use CELL CAST like Featherfinfans article suggests.
Anyways, this is good news because I've been itching to build a new tank for awhile now. This time I'll try not to skimp on materials.
Here's my plan right now for the new tank-
It will be made out acrylic, foam sheets, and plywood. Also, instead of doing a foam/cement background, I'm going to build a foam/cement midground. This midground will be a massive island. Having an island will act as a partition so that the water can have true unilateral flow. To get this river type flow, I'll point all the filter outlets in a clockwise direction.
Here' my blueprint
I'll start a cut-list and estimate the costs now. Hopefully it will be within my budget so I can start soon. I could just repair the old tank for real cheap, but that wouldn't be nearly as fun.

Anyways, this is good news because I've been itching to build a new tank for awhile now. This time I'll try not to skimp on materials.
Here's my plan right now for the new tank-
It will be made out acrylic, foam sheets, and plywood. Also, instead of doing a foam/cement background, I'm going to build a foam/cement midground. This midground will be a massive island. Having an island will act as a partition so that the water can have true unilateral flow. To get this river type flow, I'll point all the filter outlets in a clockwise direction.
Here' my blueprint

I'll start a cut-list and estimate the costs now. Hopefully it will be within my budget so I can start soon. I could just repair the old tank for real cheap, but that wouldn't be nearly as fun.