So, I've got everything ready to be cemented together. However I'm questioning if I should or should not put another ball valve or maybe even a check valve into the the upper section of my return plumbing. I drew a fast sketch of how my plumbing is going to go together, and circled the area(or actually above that area, where it's hard pvc pipe, not the flexible tubing) where I could possibly use an extra ball valve or check valve. The curvy looking tubing is clear vinyl polyurethane tubing, I picked up from HD.
What do you guys/girls think ? Should I leave it as is, or should I add something extra.