I have smoked color glass shower doors and can not get the water spots

Lime Away! (You may have to saturate a cloth and hold it to the area -- wear gloves!) Then be sure to use a squeegee every time after you shower... it's quick and WAY easier than getting off the spots.

CLR also seems to do a good job. After cleaning, (if your bathroom has ample ventilation only), apply Rainex to your shower doors and shower walls (DO NOT apply to the tub!) This will help minimize the water that sticks to them. My hubby and I keep a squeegee and microfiber towel, just to prevent the use of harsh chemicals.

Have you tried Lime Away?

Perhaps the product reviews and Q&A might assist you at this link

https://www.amazon.com/Lime-Way-Calcium-Cleaner-Bottle/dp/B0063KBGZY

Internet sources have also said that there’s been a success with this additional method.

“High-strength vinegar. I got it at the grocery store, sold with the regular vinegar, in a gallon jug. I sprayed it all over the doors, applied paper towels, and sprayed them again so it would soak for awhile. Scrubbed with a scotch brite type pad and it came off. Regular vinegar had done nothing, it had been like spraying water. The high-strength vinegar was like a miracle. I could actually see the cloudy mineral deposits coming off as I sprayed. This was after literally 4 yrs of shower door heck. I was so incredibly happy!! I now pick it up every time I go to that grocery store to keep a gallon of it on reserve at all times.”

http://cleanmyspace.com/full-strength-vinegar-double-strength-vinegar-and-white-vinegar-whats-the-diff/

I use a bunch of used fabric softener sheets saturated with vinegar.

Grapefruit cut in half, speinkle liberally with salt, scrub. Afterward, apply rained and squeegee after each shower to prevent build up

CLR and Lime Away are great, but you have to be careful with any metal it comes in contact with. It will destroy the finish on metal (faucets, handles, etc). I would start with a soft scrub type of cleaner first. It will take some elbow grease. Also, you can buy battery powered rotary type soft brushes to clean your shower with, using a cleansing gel. Keeping shower wiped dry after use or use a squeegee after use will help tremendously.

Well I actually heard WD40 works great. I haven't tried it yet but you can Google it. I was amazed at all the home items you could use it for.

the cleaner for ceramic top stove works really well

Thank you all! I well try and work my way through the list for the best one...