First of all, congrats on the hatch! If you cannot get them to eat the first bites or fry food, you can always try hatching some brine shrimp or feeding them a tiny bit of hard boiled egg yolk (powdered egg yolk if you can get it). The surefire food for free swimming Rams are microworms or vinegar eels; cultures of which are easy to find online. As far as the infusoria goes, that's a tough question to answer. How much nutrient load do you allow in the tank, how long has it been running, how many tetra and other fish that will eat the infusoria do you have, etc. In a heavily planted 29gal, there should be enough food for 15 baby rams to move into a larger stage, but that's only my intuition. Good luck raising them!