Well I have three percs, tank raised and one large bubble tip. Had them for a few months now and the bubble tip for close to a year... at first the clowns were swiming unaware of the bubble. Now what I have been doing is feeding the clowns directly above the bubble tip. When I feed the bubble tip, I bring the krill slowly towards it, so the clowns get to peck at the krill and start getting close to the bubble tip and reallize their nature... they still havent attached, but now they swim around it and they stare at it. One more thing I also tap on the glass to scare them! Is their instinc to swim into the bubble tip for refuge when they are scared. So when I tap on the glass they swim towards it but they still dont go in it....