Friday I did a quarter water change and changed my charcoal filter. While doing this I rinsed the other filter media in old tank water and rinsed the charcoal in old tank water. I also added a polishing pad to the filter that I added dry. Since then the water has seemed cloudy and tonight it seems like some algae may be growing on the glass (I do have 2 snails). However it seems like there is a white dusty buildup as well. I did rub my finger on the glass and it come right off. I plan to take a brush and just clean the glass tomorrow, but this has never happened before. What could have caused it? I do have new cories so I have been feeding shrimp pellets for a few weeks and an algae wafer yesterday as well. The water did test perfect this am.