Hi there! First time aquarium owner here, I could use some advice. I have a 15 gallon tank, put in some small rocks/gravel as substrate and then just added water and dechlorinator. Was a little cloudy from the rocks (despite having rinsed them off first) but on day two it turned crystal clear. I was planning on adding some plants in on day three, but I woke up to it being cloudy again but this time with a noticeable sulphur smell. I thought this was strange because I have not added anything to my tank except rocks and the filter. Can you get a bacteria bloom with all brand new equipment and without adding fish, food, bacteria, really anything but rocks? Is there anything I need to do or just ride it out? Thank you for reading and for any advice you can share.