Cleaning liquid solution for diagonal

[tanweeho]

Hi, apologies if this is not the right section to post.
I have a T-2 Baader diagonal which was spotless when I first bought it. But recently, I notice tiny spots on the surface when viewing against a bright light.
I tried using some cleaning solution which I use on glasses but that didn't work.
Anyone can suggest a good solution?
Thank you.

[Mariner]

Rubbing alcohol/Isopropyl Alcohol. You can get them from shelves at local pharmacies. That and some Q tips or use Zeiss lens paper. Can find them on sale at some Cash Converters. If this doesn't work, use finger and saliva to rub off the spots, followed by the above to wipe clean.

Avoid commercial glass cleaner solutions.

[Hardwarezone]

Suntan for 10-15 minutes can temporarily halt the growth of fungus before deciding on further actions, but not all equipment suitable ... such as the inner plastic/focuser of refractors ... the secondary on SCT and Newtonians ... they can melt in the focused sunlight.