Anyone who is a BETTA BREEDER here? I need to find someone who can provide me starter culture or microworms or other alternative cultures... You know, food for betta frys

Breeding my bettas is not a problem.. my male betta and his "harem" of "girls" get along well and dont even hurt each other during mating... BUT my problem is.. Brine shrimp are expensive (I buy the eggs from the shops), and they don't hatch quickly enough, and only 50% of the total quantity of BS eggs... A real waste of money...
My frys grow fast from hatching til 3 weeks old, when they die off of starvation

Thats because I can't provide enough live food (insofuria, bs) for them to eat.. they don't eat the powdered flakes nor frozen bloodworms...
the sad thing is, at 3 weeks old, the bigger frys chase their smaller siblings to eat.. but the smaller siblings get away.. so the bigger frys ironically dies off 1st... So sad...
Anyone who cultures live food? Like microworms, or others? Thanks! I would reli appreciate it, if anyone can give or sell starter cultures to me... I live in PJ area... Thanks!