i have a breeding pair i personaly started with a male and as he come into sexual matureity he became more and more aggresive, he was about 7 inches mabey more and fairly filled out. hten i found a female of equal size, so he would not kill her, i haev a freind who put a female wihthis red devil and she was onthe floor the next morning and he head splashing all night long cuase he was attacking her so bad. tlak abotu domestic voilence. he ws able to save hte female but he has to keep them sererated with a divider and then when he is sorta displaing to her in a non agressive way he lifts up the divider. i had no troubble gettign my rds to breed. make sure they haev a save palce to lay htough, and gravel to move aroudn they liek liek that. YOu canuse a flower pot with ahole chiped out, it gives a nice proctece d and secret palce for hte fish, or big pvc pipe, i ave slate rock and an old clay pot i made in middle school. they liekto put the fry in it when there still wigglers. also be aware that any and all fish in the tank when they breed will be comstered pure evil and will be brutally attacked! even plecos, but i havea feeling my plec was tryingot eat babies so be ware. also to stimulate breeding i feed them fequentlying and amply so they feel taht they can afford ot have babies and be sucsessful, and not go hungery, and that their babes will haev plenty to feed off too. one last thingi do is raise the tempiture abotu 3 or 4 degrees it stimulates a cahnge in season slong wihthte feeding, liek spring, and their confidence in survival seems to go up and they see it safe to lay. hope this helps. i ahev mine in a 30 long, with a heater gravel slate rock and face plants to create a hidden space wehre they lay eggs, no pleco nada, jsut htem, they love it!