I'd never had one of those glass-enclosed showers until I moved here and there was one in the master bath of the home we were leasing. I bought a squeegee and cleaned the glass regularly, did the usual cleaning for the tile, etc. yet after a month or so the caulking started to develop dark patches. I'd scrub and apply various cleansers...some would clear it up for a short time, but most did nothing and it kept coming back. I figured it must be mildew but how to avoid it?? I made a solution of water and part bleach and would apply it each week -- that kept the caulking white but probably compromised its integrity, making it brittle over time, but not before we moved out.
Bought a house here which had the same kind of shower. It looked clean and free of dark spots in the caulk, yet not long after we moved in, the same dark patches developed. I'm not sure whether it was an ongoing issue as when I looked more closely I saw the caulk was starting to pull away in a few spots...possibly from chemilcal treatments in the past.
My questions: - Are we doing something wrong?? - Does anyone else encounter this regular mildewing? - How do you avoid it/remove it? - Do you find the caulking gets brittle and must be replaced periodically? And why, for the love of G, do people like this style of shower?!?! Every time I see them in homes they face large mirrors, so you're usually looking at yer nekkid self while showering.
Anyhow, the only way I can think to avoid the mildew is to leave the shower door open after each use so it dries out...but in the summer here, we take a lot of showers!
TIA for any feedback!

Re: "Fishbowl" showers...ugh!
Have you tried drying off the shower walls immediately after every shower? That helps a lot. and if you could leave the shower door open as much as possible, like all day while at work, run the ceiling fan while home to move air. Maybe that might help.
Someone I knew bought something at HomeDepot that dried out the shower. If I remember, if came in a large size plastic jar and absorbed moisture.
You are lucky if the bathroom is the only place for mold with your humidity.
Good luck.
we have the same problem! I used a razor and cut out the caulk and reapplied it. Only to have it get moldy again soon.
I hate it! I think the answer is taking a towel and drying out the shower after EVERY shower. My husband lived in our house alone for 4 years before I moved in. He did this religously after each shower with a big bath towel. the entire shower was dried.
When I moved in I told him it was a waste of time and bought us a squeeqie wiper thing to take the water off the walls and doors. The problem is that I guess it gets the water off the walls, but pushes it all around the base and edges where it then will mold eventually.
So, do what my husband did and use a big bath towel and dry the whole shower everytime. Sounds painful, but I bet you wont get mold!