i had my 4 RBPs in a 90g my 2 "so-called" pair almosted spawned but the other two kept interrupting them so i seperated the male and female RB to there OWN tank..so hopfully with out the interruption of the "third and forth wheel" they'll try spawning again..ill try n condition them ,cooler w/c's and we'll see hopefully a 40g breeder will be "enough" for them