I have been running it without the eyeball. That's the way it was when I bought the house last year. I went to the pool store and bought one they had. I believe it's a 3/4" opening. Filter pressure starts at 15psi clean and when I installed the eyeball it jumped up to 20psi. The water looked like a wave pool with the eyeball installed. I have 1 skimmer and 1 return. Is the jump in psi bad for the filter? What would be the best way to increase my circulation and direct surface debris to the skimmer. I see they make a 1" eyeball that would lower the psi a little.