I have a trio of Varadero and a trio of Southern Variabilis (separate vivs of course) that I have never been able to get to breed. I have never seen any calling. The Varadero may all be female but the Variabilis I believe is 1.2 ratio. I have some El Cope Auratus that breed non-stop no matter what I do or don't do. I have been misting heavily, keeping the film canisters clean, I even tried playing sounds of their species calling and nothing. Is there any harm in adding a calling male to each of these groups? Thanks.