My whole reason to start playing with this filter was to use it as a diatom filter. it says that you can add diatomaceous earth to it . Just that at petco it was a100bucks . So that is why I did a diy . Had a cheap old school power head and adapted a pvc tube from Home Depot . That pvc tube tightly fits into the opening of the marineland micron filter . I just have been real busy with other projects that I haven’t followed thru on the diatom filter , but I am close just haven’t tested it . The issue with the marineland filter is that it has black plastic housing . That prevents me from seeing what happens inside the filter . Like the vortex was . So I have bought clear plastic containers that can be tightly closed from Walmart . I have holes drilled and now have old bulkheads that I had from many years before . Put valves on it , just need to follow thru on testing . So the real purpose of this was to filter water from a QT tank . I was thinking that I could filter down to 5microns with diatomaceous earth . Thus maybe eliminating ick , velvet , flukes , Uronema by filtering . . That with a uv filter , and hydrogen peroxide also may help . Whole idea is to QT without copper , formaldehyde or chloroquine phosphate . Maybe three different tanks each with own diatom filter to do tank transfer