Ive had males breed at 450g and a male that waited 4 years to breed. Luck of the draw kind of but ive had good luck lightly popping a different male till i get some plugs and rubbing them on the female u want to breed. It also helps to breed during overcast or rain for me. I paired 2 males together and watched them go at it to get them going but i dont think ill ever do that because they were 2 1800g males and they were not gentle to say the least. Also another method is to save the sheds of the females and put them in the tub with the male before hand or when the female just sheds leave it in there and put the male in. The funniest thing i have done is take a male on a road trip for a couple of hours then put him in with the female.... as odd as that sounds it actually worked.