Solar tubes!
 

We have the exact same shower with the exact same colors. The BEST thing we ever did was install a solar tube. We have never had any mildew at all. We still get the usual soap scum but never any mildew. We also have the builder grade fan..Anyone ever install a better/powerful exhaust fan? That is the next thing we are thinking of installing...

I use soft scrub and a brush about once per week on the floor and walls. After I am finished with that, I bought a spray bottle and have a mixture of clorox and water and spray they entire shower down. Not a problem keeping that funky mold away.

I love the idea of a solar tube!! Never would have thought of that. It's such a dark place and that would be fantastic! Do you remember the cost to do that?

We have a roman shower, run the fan and have not done anything to seal the grout. Every couple of weeks, a little mold will show up on the grout. A few sprays of Mold Armor (available at Publix), let it sit 5 minutes, rinse and the mold is gone. No scrubbing needed.

Yes, they were running a special about buying two, so , we put one large in the kitchen and one large one in the shower. Total cost for both was 1000.00 Installed and they do warranty against any roof leaks! We used the SolarGuys..... it really does help, truly!! We have never had mildew of any kind in that shower...Good luck.

we are adding a 30" ceiling fan to master bathroom with roman shower but we have no idea if this will help the mold problem
have a neighbor that added a fan and wife thought it would be a good idea.

I think the reference to use a fan is to a build in exhaust fan in the bathroom.

We have had good luck with Ka-Boom. I do a section of shower every so often, by spraying tiles, and then brushing. Tiles come out nice and shiny and clean. Usually you can tell if soap scum on tiles, by rubbing hand on the tile. Tilex is good for any mold in shower. Actually we don't have much mold to speak of, but probably because we have a water softner. (That helps soap scum from sticking to wall) Two months ago, I re caulked the bottom of shower, just so I don't have any problems. Hand held shower head helps with rinsing

Are you saying that the grout is not sealed at closing? You seal yourself before you move in?

We have a roman shower and use scrubbing bubbles automatic mist after every shower. It hangs on the shower and you push a button after you shower. We have never had any mold. They are available at Publix and Walmart and other places. I never use bleach because it is so hard on the tiles. Even on ceramic floors in difficult areas I use vinegar because it does no damage and works well.

Regular shower cleaning
 

We have just a standard acrylic (I think) shower - I used to use the Scrubbing Bubbles daily shower cleaner, but eventually the paint right above the shower head started bubbling. Plus that stuff was expensive!

Now we use a sprayer bottle with daily shower cleaner, except I make my own and refill as needed (swapping with the one in the guest bath). For a 32 oz bottle - 1/2 c. alcohol, 1/2 c. hydrogen peroxide, 2 tsp. dishwasher spot preventer, 6 drops Dawn liquid dish detergent, and water to fill bottle.

Still clean the shower about once a month with Tilex or Scrub Free or something similar.

Works for me.

squeegie and vinegar
 

After getting most of the water off with a squeegie, i spray down the walls and floor with full-strength white vinegar. No chemicals... better for the environment, much cheaper than chemical sprays, and NO MOLD,no mildew... You get used to smell, which doesn't linger too long...:pepper2:

Having just had my orientation to the air conditioning system, I wonder if your house is too humid in general? My AC has a humidity detector and will run the air extra time if humidity is over 60% in the house.

We have pretty much the same setup. We wipe down the shower daily after each use with a towel. Wiping the walls, floors, and fixtures. Yes it is more work and takes maybe 2 minutes. Well worth it. We also use about twice per week Scrub free with OxiClean while in the shower. Spray down the walls and let it wash down. Once per week I take the Oreck steam cleaner while doing the tile floors to the shower walls and floor. (About 2 minutes again) Our shower looks like it has never been used. We did not seal the grout.

However, IF you need to clean the mold that you have, I have used X14 in the spray bottle. You can get it at home Depot, or a hardware store. Runs about %6 a bottle. Works WONDERS! I used it on a home I refurbished with the showers AWFUL with black mold. Also used on the white eaves of one of our homes with a northern exposure. Comes completely clean! I will have to use it on these eves since I can see homes facing north have the discoloration too.
Be careful, VERY powerful and you do not want to inhale it. Keep a window open. But you will like it for all mold issues.

I've used bleach, vinegar and a variety of other products but discovered Tea Tree Oil is the best...not just for cleaning but staving off mildew/mold. You can purchase a bottle at Walmart for about $6.00...it's in the vitamin section. You can apply it straight or...I add it to a spray bottle, two tablespoons to a cup of water. Look it up on the Internet. Lots of uses for it and it works wonders. My whole neighborhood is using it not just to combat mildew but a mixture of alcohol, water and tea tree oil does a wonderful streak-free job on glass, mirrors and glass-topped tables. Good luck!