I have friend who runs a tropical fish store and he gets occasional suprises from his plant distributor. Auran tadpoles and Notopthalmus v. larva will show up. I have kept and reared various N. v. species and they always posed a challenge during the eft phase. Eventhough rearing baby brine shrimp can get old after week 4, fruit flies and pinhead crickets can be a hassel. I've had some efts do better in a shallow water set up with black worms, but cleaning was difficult. All in all, the eft phase can last between 2-4 years, which makes breeding them to adulthood challenging. Notopthalmus sp., Cynops sp., and Triturus sp., have very simular traits, even though I tend to take a different approach with rearing. Patience is a must with all three genera. Seems like your doing a good job. Let me know if I can help out in any way.