Algae outbreak is starting to diminish. I've started putting on a filter sock when I blow the crud off the rocks. I don't run them continually as I think they also catch good things that circulate (pods). Just replaced the heads on my DOS. It is an original release from 2015. A bit past due for the recommended 2 year replacement. I also finally hooked up the second DOS that has been sitting in the box for a couple months. I now have continual water change running. No more siphoning and hauling jugs.