I use a 6 bushel or about 55 gallon feed tub. You don't want to go too small as you can have water quality issues. 250,000 fry can produce a lot of waste! You can purchase, culture your own or wild collect infusoria to feed the new fry. However in my experience, GSH are not overly altricial and are capable of feeding on powdered flakes shortly after they absorb their yolk sac. Infusoria certainly cannot hurt though...
