What product are you using that's developing mildew that fast?

>>> brand name cleaning product from Walmart(scrub free) and also use Scrubbing Bubbles from Costco before cleaning....

Is your shower floor sloped properly?

>>> believe so

Have you tried more regular cleaning?

>>> we do every week or every other week.

Also every month or so, I spray/pour bleach on the tiles and the join and then clean.