To get them to breed? Try dimming lights and music? I am really not sure, I put a orange female in with a black male and he mated within hours. Mollies can mate with guppies and vice versa so watch them, it is easy to spot and he may ignore the mollie if that happens put them in the nursery alone and see. As for the nursery set up, no gravel, maybe plastic plant hornwort java moss or something. All of those offer hiding spots but live plants offer infusoria for them to eat. I am using a Tetra Whisper 10i right now, has no flow adjuster but seems to not be too strong for my guppy fry is a little cheaper than a sponge but both are good choices. People have used HOB with success. Hope things go well.