I feel the same, as my pair is also quite young. Their bodies are the size of an american half dollar. The tank I am using is a 55 us gallon, so I believe I have stable enough water parameters, I feed the fry with a wash of fry food using a bulb syringe washed gently over them.
What, if anything, have you done differently this time that you feel has brought you so far? I totally stole your filter idea so there is little or no current in the tank, and the last batch did make it further than ever before.
How do you soften and lower your waters ph? I see seachem discus buffer, but am nervous about trying it without another,more experienced opinion. How often do you feed bs to your pair to keep them in condition?
Sorry about the questions, but discus and angels are so closely related in behaviour and husbandry needs, I figure your my go-to guy!