I've just been using the generic stuff, got a 12 pack at Lowes. The secret I've found is to dry the end of the frag, then apply a thin coat. After a few seconds, put a small blob on top of that. Quickly press it and turn a bit. Hold it firmly for 1 minute. I do this at night when the little monsters are asleep. Turn off the powerheads for an hour or so to keep the current from knocking it loose.. These have all stayed put.