I bought a house that has a pool... The pool is a 30,000 gallon in-ground vinyl. I have two skimmer boxes, one bottom drain and a Polaris. The pool also has two sets of jets... two by the stairs, one in the deep end and one in the shallow end. The pool has two three-way valves located by the pump (a DE pump). One is black and one is white. The white valve is before the pump/filter and the black valve is after. I've attached two pictures. I have two questions.
1.) I believe (based upon trial and error) that the white valve controls which skimmer box the water is being pulled from. It seems that if the handle is pointing at position 1, the one skimmer box is on and the other is off. If the handle is pointed at position 2, the second skimmer box is on and the other is off. If the handle is pointing at position 3, all water to the pump is cut off. If the handle is pointing at position 4, both skimmer boxes are on. I've confirmed this by just moving the valve and checking each skimmer box for movement. My question is, how do I isolate the bottom drain? I'm trying to vacuum the bottom becuase I have residual dead algea from an outbreak that occurred a few weeks ago but I don't think I'm getting enough suction. The vacuum seems to stir up more of the stuff than it sucks up, so when I'm done vacuuming some of the particles are suspended in the water and later accumulate (again) on the bottom.
2.) With regard to the black valve, anyone have any idea what each position does? You can see the boster pump hose for the Polaris. I know one of the positions will cut off water to the Polaris, but I'm not sure which it is. Also, this valve seems to operate differently from the white valve... the white valve seems to cut off water to which ever position it points, whereas the black valve doesn't... I'm a bit confused.
Can anyone help?