Solar panel scratch?

I was working on my first solar panel cleaning job this week using WFP with a Reach iT brush and it looked like maybe the brush was leaving light scratches. Has anybody had this problem? Do I need an actual solar panel brush for my WFP?

Are the panels glass or plastic?
Some older versions were made with plastic.

Never had a prob cleaning solar panels. Never scratch. Good point r they glass or plastic

I use my older WFP brushes on solar panels, just in case

They are glass - only a year old.

Did you get up really close to inspect it, or was it from the ground? This week I cleaned panels in an area that has a cement production plant. After 1 pass it looked awesome, then they dried with what looked like scratches - random swirls and brush strokes etc. I got on the roof and rubbed at the “scratches”, but it was actually the start of the cement dust being removed. Took 3 passes plus using a detergent mix to get it all off.
Lesson here - get up close and personal with the panels if possible to inspect the ‘scratches’. If you cant, I would wrap a clean, damp microfibre cloth around the brush head, and wipe a panel to see if it’s still dirty.

I was unaware that panels were of plastic, thought they were all made in glass version.

Sent from my GT-N5110 using Window Cleaning Resource mobile app

We do a lot of solar panels here in Cali
My experience has shown that most panels need a little extra help by using a soap with your cleaning.
Titans Solar Gleam works great!

The “scratches” might just be lines in the dirt. Were you using a nylon or boars hair brush?