Dwarf Gouramis are a mystery to me!

dwarf gouramis are I think the toughest fish I've ever had. I had a pair one time that spawned twice in extremely suboptimum conditions ( somewhat neglected tank, fed a steady diet of plain flakes on an irregular basis and infrequent water changes.)

they had probably about 100 fry each time but they are really really tiny fry and I didn't have the equipment or the space to raise them, so I let them be a snack for the rest of the tank inhabitants. perhaps the genetics from the breeder you're getting them from are just bad?

50% water changes might be stressing them too. maybe try doing weekly 30% changes instead? mine almost seemed to like the infrequent water changes, seeing as how they built a nest and spawned twice in the 8 month period I had them ( I sold them and they were still perfectly alive and well)

dwarf's aren't terribly picky fish, their water perameters are not of great importance, but stay away from acidic water. The ony real concerns are the lighting and tempature. They need to have shade, and will generally stay in a corner if not provided some shade. Their water tempature also needs to be held consistantly at 78F for them to do really well, other than this, they are pretty simple!

I recently bought a pair of dwarf Gouramies, and they are doing great... they are good community fish, I keep them in an outdoor 300+ gal pond and they have many caves and places of shade i do once a week or even twice a week partial (20%) water changes. These fish like little circulation and places to hide.