I feed them with micro waffers from Hikari. They love it much better than golden pearl. I order 4 Oz of golden pearl, 500-800 microns. My betta taste it and spit out. They love micro waffers; I just ordered 2.2 lbs of micro waffers yesterday for my betta.
If you want to share, let me know. I make you a good deal.
It is good size. Big adult betta loves it too. These are made in Japan (not China). It is also soft. I used to squeeze it with my finger to break them into smaller piece with no problem.
Tan