just one to watch with mellon, i used honey due, most of the fish especially the bn plecs loved it, but then i knottiest the ehiem wasn't running right
cut a long story short as the fish were eating the melon small particles (less than half a mm) got broken off into the water, they then clumped together as they went up the suction pipes of the ehiem pro 3 and blocked both suction pipes to the filter, took me an hour to figure out why the ehiem wasn't pumping any water, both were reduced from a flow to a trickle until i had to blow all the melon particles out into a bucket
have to admit i had given them half a mellon to munch on over a couple of days.