Hey guys so I am working on the return line that is in the overflow box until my flex pvc comes in for everything under the tank. My questions is do I cement the two spots in the picture below? I just don't know if it gets cemented because it is submerged in water and the point of what if I have to remove it from the overflow box. Might be kind of hard unscrewing with the elbow.


The red line on the pvc is just saying it would be cut, didn't do the measurement yet or cut the pipe.