I'm not quite sure why you think you need fluorescence, it is not the standard way to analyze bacteria, colorimetric is, like crystal violet. Without knowing more details, what your doing sounds appropriate for gram positive bacteria. However, you would be missing gram negative. If you need both, look into a simple gram negative counter stain (i.e. safranin). Also, most people look at cfu which would be plating and growth, but again maybe this isn't relevant to your experiment.  

It depends weither looking total viable counts or total count which I donot advice using stain with microscopy.

When crystal violet is used alone, that will stain all the cells whether gram-negative or gram-positive, but the only point is that they may not be all viable. To count the viable cell CFUs are count, which is through plating and then the use of a colony counter.

I think ,,you should follow CFU method.

I´m agree whith Chandni, but you should count cell whit Petroff Hausser or Neubauer camera, an then you can know the actual number of total cell in yuor suspension

es.slideshare.net/uscbio225/viabilidad-y-conteo-celular

www.microinmuno.qb.fcen.uba.ar/SeminarioRecuento.htm

www.diversidadmicrobiana.com/index.php?option=com...id...

absolutely you can use light microscope........... u just doing simple staining. and CFU Method is best way...