Bests & Worsts Reviews from Amazon

I've had this humidifier for 1.5 years and use it mainly in the summer when it's hot and dry in California and also sometimes when I'm sick. After about 5 months, I noticed a brown film of algae forming on the bottom of the blue tank. Since the bottom doesn't screw off, it's near impossible to clean. I tried using a toothbrush, pipe cleaners, and clorox wipes, but the opening in the bottom is way too small. After a half hour of work, I managed to get a bit of the algae off, but there's still a considerable amount left. I also tried the vinegar+chlorine solution, as the manual suggests, but CLEANER/BLEACH/VINEGAR ALONE WILL NOT REMOVE GRIME THAT IS PHYSICALLY STICKING TO A SURFACE. You need scrubbing to do that. See my picture here: http://www.amazon.com/gp/customer-media/permalink/moI3GE7KRZLLWD/B001ADL1SG/ref=cm_ciu_images_pl_link It's gross to think that the moisture this outputs into the air might have bacteria growing in it. Perhaps this could be prevented by using sterile/boiled water--I'm going to try that and see if it grows back again. In the end, it's disappointing because this problem could have been avoided by including a few screws on the bottom of the tank.