This most probably has been done before but here goes again. The best possible first food for egg layers especially gouramis and tetras etc is boiled egg yolk. First hard boil an egg, take only the yolk, put into a piece of cotton cloth like a handkerchief . Push it through into the tank. You...
Mate I'm sorry. You can use methylene blue and/or alder cones to help reduce fungus in future spawns, but you still need to check frequently to remove any fungused ones. There's more info about that in the thread I linked before.
If you want to give it another shot, at least you know that they've spawned once, so they can again Feed them some quality foods for a week or two, then do some large water changes with water that's a few degrees cooler than the tank temp (replicates the cooler, rainy season when they spawn in the wild), and you'll be collecting eggs again in no time I'm sure.
Interesting hadn't really thought about that. What is the definition of a master breeder and I will be able to tell you if I fit in there.
But I have breed around 100 different species of freshwater fish and most of them in commercial quantities. I have also always tried to use best practices when breeding fish. I have also breed some fish for the challenge and have experimented a lot on how to get fish to spawn. A master breeder not sure, you decide.