I have been washing and washing my garage floor, using bleach, pinesol, anything I can to kill mold or mildew. Now I have decided this is not mold or mildew, but something coming from the cement floor itself. What can I do to get it to stop. It truly looks like mold. I live in Hawaii, and walking barefooted leaves foot marks, and floor always looks dirlty.

J. M. Leal, June 2010

It's called Effllorescence.
It's caused by waterborne salts passing through the masonry.
It happens in new builds when the cement was allowed to get wet, but it usually dries out after a few weeks or months dependent on climate.
If it's continuous it means there is water seepage through the floor from groundwater.
Was a waterproof damp course installed before laying the concrete?

Big Softy, June 2010