Peppermint bristlenose keep as colony or seperate

aquired 7 peppermints to try and breed 3 males and 4 females most are 10 cm plus, at the moment i have them in a 150cm tank by themselves, also have 60*45 tanks in a rack where i have been breeding common bn successfully, what are your opinions about keeping them as a colony in a larger tank or seperating them down into pairs in smaller tanks? Have had two spawns in the colony but both dissapeared in 3-4 days may have been eaten looked like some shell reminants where they were in the cave there are no other fish with them. i am reluctant to mirco manage them by removing eggs and tending to them seperatly. The male that was sitting on the eggs was one of the smaller ones so maybe inexperienced but i cant choose which females lay where or know which female layed the eggs.

Split into pairs and trios, much better breeding success that way

I totaly agree with Doug! You could also try yo keep the females separately and when are getting full of eggs just drop one male inside the aquarium. I have a friend doing like that and he had good spawns keep also an eye on the male if you are using more than 2 femlaes he can get tired or as soon as the females are droping eggs inside the cave move the father in a separate aquarium but here you need to pay attention when you are mooving the eggs or the cave with the eggs. Good luck!!