make sure to keep them under a ledge in the shade. Mysis and cyclo was their favorite in my tank but they will eat anything meaty. Feeding every second or third day will make them multiply like crazy, i moved to a once every 5-7 days and they didn't do as well. Use a turkey baster or something with a big opening to slowly drop the mysis on them so you don't hurt them by having a small fast stream of water shoot at them in case you accidentally squeeze too hard :irked:
Keep them under a ledge or in the shade somewhere, and learn to feed them at a certain time every feeding. This will hardwire their sensors to open at that time for feeding nomatter on a feeding day or not. I had cyclo mixed into the mysis so if they didn't open or weren't open i would scrape some cyclo into the tank and they would be open in 5-10 mins fully.
I feed mine all the above. I tried to cut up silver sides but they spit it back out after a few mins. I also feed mine squid and sometimes krill. Here's a pic of all three. The was a day after I got the yellow, the heads open up much larger now. I'll have to get a good pic with a close up of all three fully open ready to EAT