what does this do? and it is causing a leak

[pbeckman]

when I move the valve to the open position for both pool and spa, the pool and spa water levels drop a little (about an 1/2-1 inch a night). if i have the spa closed it does not drop. also, what does the black knob on the right do?

Thanks,

 

[jblizzle]

It is a plug for you to inject lubricant ... it should not have anything to do with water level changes (unless you see water dripping to the outside).

 

[pbeckman]

any ideas on where the leak could be? valve, or pipes?

 

[Bama Rambler]

OK, if you have the pool valve open and the spa valve closed it doesn't drop? Is that right?

What happens if you close the pool valves and open the spa valves, so it's just circulating the spa?

 

[pbeckman]

OK, if you have the pool valve open and the spa valve closed it doesn't drop? Is that right? - Correct

What happens if you close the pool valves and open the spa valves, so it's just circulating the spa? you know, I have not tried that. I will try it tonight. tks for the suggestion.