I used to think that when I backwashed, some of those palm seeds(needles) might have gone inside the grids and they are coming out, but its been more than a week since I started observing this. So doesnt seem like that.

About the valves, I am not that sure if I am doing something wrong there. I have attached a picture of our setup.
As much as I could see there doesnt seem like a bypass where it bypasses the filter, correct? This is exactly how the valves are set now.
One thing is on the returns I can see that there are 4 pipes going out,
1. to return 2. to water feature 3. to pop-up cleaner . I dont know if the 4th one is going to the heater? So what happens if I close that one?

Appreciate your time.