I have changed up my system and no longer need this sump. The dimensions are 30"lx24"dx20"h - 60 gallons. I have used this for about 8-9 months with no problems.... it was built by RC here in town. I just replaced two of the sides and resealed the entire unit. It was filled in my garage for a few days for leak testing and all is tight and dry. I also added a 2" piece of 6mm glass along the left hand side for euro-bracing as I found that the side had a slight bow to it when it was filled... this fixed it. $80.00.
Here is a pic;
There is now one 1.5" hole drilled in each of the right hand side compartments for a drain and a return. The sump was designed to have an area for a skimmer, heaters etc.... then flow into the longer area for a fuge and then into the last area for the return.
Thanks for looking.