Cleaning Mk2 i screen from hard spots

Hello all,

Please see the pic above. I have these spots on the screen and i cant seem to be able to get rid of them and they are getting annoying.

i use my watch primarily for diving and I always clean it in clear water after dives but the clear water is really hard in my area. I tried several things to clean it:

1. Used a toothbrush with soap

2. Used a cloth with some vinegar and rubbed the screen a few minutes

3. Left the computer in clear water and some dishwasher for 6 hours

None of the above did anything….

on top of all this, the temp sensor must be dirty as well, as i dont get accurate reading anymore as i used to.

I would appreciate some suggestion how to solve this.

thank you