I would not run the diatom 24/7 but I have one and it saved my tank when it crashed. I am still not sure what happened but every thing was dying and the tank looked like someone poured milk in the water. Did many WC
over a 3 day period and it never got better. A friend said try my diatom, so I did. Had the water better in a few hours and after running 24 it was crystal clear. I will never get rid of that filter.
They make carbon that you can use with that filter if you want to polish the water. I use it once or twice a year if I get a lot of free floating particles that won't settle out. Never been a issue with my reef.