I'm assuming you mean Fatheads (Serranocirrhitus latus). I have a group of 5 with Bartletts, Dispar and Pascalus. The big issue with Fatheads is getting them to eat initially, but once you do, they are typically pigs. You should be fine mixing as long as you have good rock cover and you add the Fathead first, or thru a two week stint in an acclimation box.