I have a 29 gallon tank, it’s had 2 clownfish for 2 weeks now, and I am about to change my water for the second time. I have seen any visible algae but when I had a freshwater tank there was significantly more at this point. The fish store employees also told me to sandwich live media between two sponges for my filter, and just rinse it off with tap water whenever I change the water. Is this information correct? And am I missing something about saltwater algae? Also there is a gray residue building up inside the filter


