Plumbing my fuge and skimmer

Well, I have another question about sumps as I'm sitting in my basement building my 1st one. I'm going to run PVC from overflow box down to my fuge compartment and skimmer compartment with a ball valve under the T leading into the fuge. This way I can lower the flow into the fuge and keep most going into the skimmer.

My question is....should I put another valve right before the PVC dumps into my skimmer compartment as well?? This way I can completely shut off the flow from the overflow box and by just unplugging the return pump. I like low flow during feedings.

Any negative to this idea???

 

that is how I did mine, and it working great

 

There is nothing wrong, but with the return pump off, there is no need to close such a valve. There is no overflow. You will need a ball valve on the return line for quick isolation so nothing drains back and the tank stays full.

 

Won't the siphon from my overflow box keep flowing with the return pump off??