Plumbing question?

[JAnderson1]

What would be the point of having the return "T" off and return to the over flow? Is there a benefit? I'm trying to plan out my plumbing. Thanks

 

[bjohanson1234]

To help adjust the flow back into the tank. Adjust it to maintain the proper return flow into the tank so the overflows can keep up with the water being pumped into the tank.

 

[JohnVH]

I have the same on mine to help dial in the flow