My moms new place has a screened in patio, but also has some kinda vinyl sliding windows in it also.

The front ones have mass hard water spots from the irrigation system. I tried to use soap and water to get it off and it helped a tiny bit, but not good.

I've googled and found a mix of vinegar and water will remove the spots off isinglass boat windows. From the YouTube videos I've watched isinglass is a fancy name for plastic windows.

Any of y'all tried it, or know something that may work better?

She's still in the hospital, and I'm trying to get everything unpacked and looking good for when she gets out.

The window in our back door is made of some type of plexiglass. Over time it will grow a kind of hazy patina. Ruthie gets it right off with 50/50 white vinegar and water.

We also use it to routinely clean the coffee maker and dish washer. Great rust remover, too.

__________________
Music/Sports/Beer fan

These windows aren't hard like plexiglass. There a lot like the windows in my old Jeep.

Look into a product called crystal clear 550 from Winsol.
I have used it on glass and on painted cars. It is an acid so make sure it is safe to use on plastic before buying it. The folks at the sales dept are very helpful.
Just read post #3. If the windows are stitched to a fabric I would not use Crystal Clear 550. It may well deteriorate the stitches.

Here's what I use on plastic windows - like the soft convertible windows and even on plastic headlights.

Meguiar's(R) PlastX™ Clear Plastic Cleaner & Polish, G12310, 10 oz., Liquid | Meguiar's

It's about $10 or so.

__________________
Thread Killer.

You beat me to it! Meguiar's Plastic Cleaner and Plastic Polish work great.