Did it ever get finished?
Well there is good news and there is bad news which is why I haven’t updated in so long. The tank did hold water. I initially had a leak at two thirds full so I had to back it down and ended up adding liquid rubber as I determined the stresses on the hard epoxy shell were too great. After that I enjoyed almost a year without any issues until my dryer caught on fire and completely destroyed my home :-/ unfortunately it was a total loss. With everything that I have learned during this build my next home purchase and subsequent tank build will be concrete to ease any worries.
I will say this to the naysayers, the tank held water with no leaks after the liquid rubber was applied and I enjoyed watching my puffer fish happily swim in his own private ocean ha thanks for all the wonderful memories gents.