Dave,
I cracked my fuge just like that turning the PVC into the bulkhead - my guess is that's what you did too.
If you can get a heater and a powerhead in the tank and drain it an inch or two below the crack, you are welcome to come down and get some weldon (acrylic
glue). It is so fine and thin that the cappilary action of it will bond that crack as if it were never there and be as good as new.
LMK - if you want, take the tank apart and bring it down and ZI can glue it for you - for a frag of course.
Jim