Cleaning and Stain Removal - Cleaning fiberglass shower/tub

I have an old one-piece shower/tub surround in the house I just moved into. I think they never cleaned it all all. I had a cleaning service in here before I moved in and they helped a lot, but there are still some stains on the floor of it, looks like just imbedded dirt, that won't come out. I have tried soft scrub and tilex and the daily shower sprays hoping that repeated use would help, and also scrubbie type of sponges, but it just doesn't get really clean looking. It is beige color. I would hate to have to replace it since it's ok other than the grungy look, no holes, etc....

Any ideas?

Assuming this is a fiberglass tub, it sounds like you have tried all the recommended cleaning methods. When moving into a new home where previous tenants used abrasive and harsh cleaners, this can permanently damage the protective gel coat on fiberglass. Hard water minerals can also blast away and etch the gel coat. The tub/shower bottom is usually the area where the most wear takes place. Once the gel coat is worn away the subsurface, which is porous, tends to absorb soils, oils, and stains.

Try making a paste of BarKeeper's Friend or Zud and water and treat surface and let set to see if will dissolve any imbedded scum and minerals. Then scrub with soft brush or sponge. If there are signs of improvement, repeat. Another option may be the use of the non-fume oven cleaner (not the regular caustic kind). Spray on and let set and then scrub with brush or sponge. Rinse. Buff dry.

If further DIY attempts fail, then you can contact a professional who specializes in fiberglass gel coat repair. Check your yellow pages. If none are listed, contact a local plumbing supply store.

That is what it sounds like to me as well. Soil is getting down into the tiny scratches in the wear layer, were its hardest to remove. You may want to look into either a tub insert or refinishing.

There's something called "Gel Gloss", which you can buy at Home Depot or Lowes, that might help. I've used it several times in my bathroom and found it to really help get out stains and shine things up, too.