I do not have a spa, but there is a bottom drain. When I bought the house, there was a suction robot in the basement (does not have wheels), but we were unsuccessful at getting it to work last yr. There is no dedicated vac line.
where was the suction robot connected? What happens when you turn the valve to left (blocking flow from the right side pipes). What happens when you turn the valve to the right?
Can you pull back and take another photo?
We attached the robot to one of the skimmer lines, and it wouldn't work. I have tried two robots.
When I turn the valve my husband did not notice anything happening, he was holding his hand over the skimmer intake, and nothing happened. He was looking around and did not see anything happen. When I was at the pump closing off each end did not increase the filter psi and it did not constrict water to the pump (i could tell by looking at the window).
Yes, as it will help direct more suction to the skimmer that you're plugged into, plus, it will prevent the cleaner from getting stuck on the bottom drain. You shouldn't have to close off the bottom drain line all the way, but then again if you do, you can think of your cleaner as a moving bottom drain.