Hey guys. just wanted to throw this out there to see if anybody has ever had this on a scrubbed system. About once per day around noon my reef aquarium will give off a sulfur smell for a few hours. I started noticing this After I installed a 13 watt UV in my sump about a month ago. The UV and scrubber are the ONLY filtration. The UV was installed to help cut down on glass cleaning and it has worked wonders for that,,the scrubber takes care of the rest! My tank and creatures inside are all thriving! But once per day the room gets a little smelly