I have a 3-way valve between my skimmers and my main drain (my skimmers are plumbed into 1 line unfortunately). So, I turn my 3-way valve with about 20% open to main drain and full open to the skimmers.These are great insights, and much appreciated. One question for these low-flow speeds: do you guys close off your deep end drains in order to boost the flows into the skimmers? I have two skimmers and a double main drain, and have previously left them all open except when manually vacuuming.
I always like having some suction from the main drain because if a weir door would be suck then there is always fluid suction from the main drain, so the pump does not suck dry.