what is the best way to raise betta fry

Betta fry only eat live foods! I can't emphasize that enough. Bettas live off their egg sacks for the first 3 days but it's good to introduce very SMALL amounts of food to the tank a day after they emerge from the egg so that the big guys can start eating right away. Feeding too little is a little better then feeding too much, as you don't want to spoil the water killing lall of them. A good starter meal is: Week one: infusoria, vinegar eels; week two, vinegar eels & microworms; week three, microworms and baby brine shrimp; week four, microworms, baby brine shrimp, brine shrimp, dried food; week five, microworms, brine shrimp, dried food; week six, brine shrimp, dried food and pellets. You can read more at http://www.petfish.net/articles/Bettas/Betta_Breeding_Walkthrough2.php

Betta fry needs frequent change of water, at least 20% of it in able for hem to grow fast. I also put some pebbles because it serve as filter(I'm lazy when it comes to siphoning). I just feed them with boiled egg(yellow part) them wrap it with stockings then soak it gently. Fry are so tiny so they need tiny foods. Getting live foods in local fish stores are hard to find so my last option is feeding them with egg yolk. Daphnia is also a good source of protein for betta fry. Live foods make them grow faster. And lastly, i use air pump(small amount of air) to make sure they all survive.