I have been owning this pool since last August but after a reading a post in TFP it motivated me to go and see the skimmer inlets
Of the two ports
1. The one marked in Red is what pulling the water to the pump
2. The one marked in Black arrow, I am not sure why it is there, I see it is filled with DE (I tried with a tiny stick)
Both of my skimmers exactly the same, I don't know the use of the dead port (The port marked with black arrow). Also, recently I switched my values in such a way that;
a. pool main drain fully open,
b. skimmer one fully open,
c. skimmer two fully open,
d. Spa main drain fully closed
I noticed skimming efficiency reduced a lot(the force of water sucked into the skimmers is reduced).
Can someone help me in understanding my system?