Guppy/endler crosses tend to be fine that way, any I have had in the past when bred to virgin endler females produced some lovely fry. I hope he isn't sterile either!
The female is pregnant. She mated with my black male and I am eagerly anticipating her fry! She seems to be taking forever though. I will need to check the start of this thread but I think she might only have a week to go. Super excited at the thought of little black babies (hopefully!)
Then the plan is, take a female black baby out, put her into the 30L and put the endler in with her. Hopefully they mate, Take the endler out and let the female stay in peace! That's my plan anyway!