First, thank you to all those who have contributed to these forums; the information herein has helped me maintain a nice, clean, pleasant pool.
Now, my question: I hired someone to close the pool last year (brand new pool owner), and I don't really remember if they jumped into the pool with a screwdriver or not, but what I have this year is:
Skimmer, works fine.
Main drain: no detectable suction from it, and if I look at it closely underwater or from above, it very much appears that there's some sort of plate just under the protective grill/grid.
The line from the main drain has the red cutoff valve in the "FLOW" position, parallel to the line.
Is there a plug I need to go in with a screwdriver and deal with (with the pump physically turned off and unplugged as well, and the 3-way valve set to Skimmer 100% or OFF, one or the other), or is there something else I need to look at?
Is there a better test than being upside down underwater and watching a helicopter or leaf _not_ get firmly attached to the main drain, and my feet able to almost cover it without noticing suction?