It sounds like you have them setup very nicely. Some people don't have to do a thing for their auratus to pump out clutch after clutch, but I have to tinker with mine a little to get them in the mood. Here are some things you might try to stimulate them to breed for you:
Try shortening the photoperiod drastically for a week. My auratus won't breed unless I do this. Make sure you don't cut back on light so much that you make your plants suffer, but enough to make a difference. When I do this, the light's on for about 3-4 hours a day.
Also try putting a pothos leaf (or leaf of the like) on the petri dish underneath the hut. This, again, has been a key factor in getting my fussy auratus to breed!
Make sure your tank is heavily planted, auratus can be shy at times, and they seem to feel more comfortable when they have the abibility to hide if ever startled.
And finally...MIST!! Lots and lots of misting gets my male calling like crazy, so this is something that should be tried as well. Increased food intake also seems to play a key role in priming darts into breeding. I hope this helps and good luck!
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Randy
www.fruitflyspecialties.com