Black mold and rust stains

[weepingmoonblue]

Ok, there doesn't seem to be any memories section on here, so i don't know if this has been asked or not. (please do memories, someone, it would be so awesome) But, i live in a very humid area, and black mold grows around here like nobody's business. It's gross, and i hate it. i've been able to keep it under control and clean, on things like walls and ceilings, but it has gotten into our bathroom grout, around fixtures, and i can't seem to get it off. Any suggestions would be helpful, but i'd really love it if someone had ideas about how to clean it with the most "natural" cleansers possible, because i have really bad chemical allergies, and asthma.
Also, our water is so hard, and so iron-rich, that it leaves red-brown rust stains on the grout around the tub, toilet, and sink faucet. Again, it is a grout problem, and i can't seem to get this gunk off! Does anyone know how to get rust-stains out of grout and porcelain, without too much chemical hassle?
Thanks for the help! :)