I had hydra in a discus tank a week or so ago, I added about a dozen 2 month old 3-spot gouramis and they ate them all in about 3 days. Only fish I know of that will eat them, the trick is to find the gourami fry that are small enough to mess with your apisto fry > Sunday, I was doing water changes and to my absolute horror I discovered > Hydra, in the Pleurotaenia mother and fry tank. These things were > everywhere!! They sure weren't there before I left for Montreal on > Saturday!!