Help with valve

[smitt]

I recently moved into a house with Salt water pool. I need help with one of the valve, which I think is the water coming to the pump from pool. It is set to close. I was wondering if there is any reason for the valve to be close. Could it be something else rather thn the water coming to pump from pool (Picture included).
I have 2 skimmers, multiple returns to the pool. 1 Drain at the bottom.
Its the valve on the right on the picture.
Thank You

 

[BadOleRoss]

I hard to tell where some of the plumbing lines are going to, can you take a picture from a side angle?

 

[smitt]

here are 2 more pics, if they help. I can take some more if needed.
Thank You

 

[duraleigh]

It is water coming from the pool to the pump but from three different sources. Probably a main drain and two skimmers but you'll have to experiment with the settings to see which combination gives you what result.

Label the settings when you get it resolved.

 

[smitt]

is it not best to open all three? I opened the 3rd one for less then a minute and there was lot debris (mainly leaves) that came in the basket. So I closed it again.
At the present setting, both skimmers seem to be working.

 

[bobby1017]

It prob regulates the flow between the drain and the skimmers, maybee the valve you opened was from the main that had collected debris. I think as a general rule it's good to have water pulled from both the skimmer and main drain, thats how mine was set from the beginning, if i want more skimmer action I can close the main drain and all the water will go through the skimmer, or visa versa.