White fibers blowing from return jet

[Deskett01]

Have 27' round above ground pool (18,600 gallons) with Cartridge filter. Had for 6 yrs and have not experienced this problem before. When pool lights on at night, I see little white particles floating around & blowing into pool from return jet. Just replaced cartridge filter 2 weeks ago thinking old filter shredding in pool (was pretty old & dingy).
PH- was 7.5 dropped a little to 7.2
Alkalinity- 80
Hardness- was 0 (pool supply store tested water & said not to worry about hardness level until closing) I don't remember in previous years not adjusting it, so this week I raised it to 140 within 3 days.
CYA- 40
Chlorine- 3-4
I added algaecide & shocked this week as well. Water has been pretty clear all season until 3 weeks ago when I could see it was getting a little hazy. Not bad, but I could tell. Thats when I noticed tiny particles floating in pool (some look like air bubbles). I thought it was air coming out of jet, but today I put skimmer net close to return jet & can see some of the particles are getting trapped in the net, not all.
What could this be?
Oh, FYI - feel like there could be more suction in skimmer. Seems like its kind of week. Not positive, been awhile since last season, but for me to to think that I'm probably right. (Just like a car you always drive. You know when something doesn't seem right!)
Any ideas?

 

[Deskett01]

These are some pics I took. Maybe it will lend some insight as to what I'm dealing with.

 

[kellyfair]

Those bits in the first photo are the fibers, right? Second photo hard to tell if liner design is getting in the way.

If you catch them in your fingers, what do they feel like?

I would have guessed same as you - shredded cartridge. What else do you have - a skimmer? do you use skimmer socks?

 

[kellyfair]

Have you inspected hoses thoroughly? Connections?