My girl is in week four of flower and my humidity is a little high (upper 50's to low 60's). Inches higher after watering and she is getting really thirsty. I have a small grow space so no room for dehumidifier. I have researched on line but a little worried about using "store bought" dehumidifier products because of possible chemical contamination. Rock salt or bamboo charcoal seem to be the best approach. Any suggestions?