Hikari is the best and most reliable brand that I know of for betta foods. They really know what they are doing and when you buy something with the Hikari brand on it I think you can be sure of its quality and ability to be good for your fish. They take special care in their processing to protect the quality of the foods and I trust them a lot. I think the fry will be okay through their first 8 weeks with the Hikari First foods for them After this you will need to see what their size is and if they are at least big enough to tell what their sex is and you have them seperated to the male and female jars and tanks then they need to be started on something more nutritious for them ... there are other things they can have then but if you feed them bloodworms at that time I am not sure they will be ready I think it should actually be the baby brine shrimp. I know you said none of that but that is unfortunately the thing that bettas are raised on and they need live foods to eat or I am afraid they will not eat. It is something about the action of the food that draws their attention to it. Let me do some more investigation to see if there is a substitute but most breeders that I know of have never tried anything else so I do not know that there is anything that is on record for it.