Hi Dann, might i suggest a page in the supplements section maybe dedicated to lens carekeeping for newbies.

for instance, i have a ring on my dartboard lens caused by water seeping through it.
what i realize now was that i didnt clean it quickly enough when it got wet, and as i was in a room with air conditioning on, the cold air kinda made the water i dunno vaporize or something which led it to create the ring.
a mistake recent of mine, i forgot pezs review that hydrophobic radar not fully hydrophobic. same thing happened,
got water on the lens, didnt clean it fully enuff. got some water on it. went inside my car with airconditioning on full blast. next thing i know, small 'specks' of what i presumed the water earlier freezing in the lens. so got some tiny specks on my radar. which sucks. its not a 'ring' tho just a speck but sucks nonetheless.

nehow, lesson is, dont leave your lens wet in an airconditioned room or place or maybe even winter ???

The deposit is the minerals in the water.

Try licking a q-tip and giving it a good scrub.

oh cool for that tip. ill try that.
thanks