Clarification on valve configuration at pump suction

[newowner77077]

Hello all,

I have two ball valves at the suction header of my pump. My guess is that one of them is for the line from the pool skimmer (top of the pool) and the other one is for the line from the main drain (bottom of the pool). One of them is open (one on the left) while the other one is closed (one on the right). Ever since I moved into my house (aka took ownership of the pool), the valve positions (on/off status) have remained unchanged.

Is this how it should be set-up typically? Assuming that my understanding of the piping configuration is correct, is there any reason I cannot have both valves open and take suction from the skimmer line as well as the line from the main drain? Is there any advantage of switching the suction sources?......take suction from the main drain only?

I would very much appreciate a detailed explanation on what the recommended set-up should be.

Thanks in advance.

 

[pooldv]

First, those ball valves only last a few years before they swell, stick and the handles break off. Your plumbing assessment is logical and probably correct. Mine is similar except that it has a 3way Jandy never lube valve to switch between skimmer and drain or blend. Pics of my equipment pad are in my build thread, link in sig, if you want to replumb some day.

My normal state is 80% skimmer and 20% drain. This to get more skimming action but allow water flow from the drain if the skimmer gets clogged. When I brush the bottom I move all suction to the bottom drain and sweep the debris to the drain so it gets picked up by the filter. When I want max skimming I will switch to 100% skimmer. But, we have so many trees dropping stuff that our skimmers will be full to the top and shut off water flow to the pump.