I'm SO happy the baby is doing well! I wouldn't worry about the actual volume of formula you are feeding him. I never used a syringe (fear) and therefore never measured what Rocky ate. I just let her eat until she refused more food and scampered off to play or fall asleep. Make the formula is nice and thick at this age and you will find it easier to feed him thicker formula by spoon than the syringe because the syringe can get clogged with thicker formula. Thicker formula also lets the baby (and you) go longer between feedings as it doesn't exit the crop as quickly as watery formula does. Spoon feeding can be messy especially when he tries to dive right into the spoon so make sure you clean him well after meals. Just like in human babies, as they start eating solid food, they don't require feeding as often (allowing both baby and parents to sleep through the night). I think a level teaspoon is roughly 5ccs but dinnerware spoons vary a lot in size. You may want to use a measuring teaspoon if you want to try to track the volume he eats. Or you could measure the formula into a syringe and squirt it into the spoon before feeding him. You should get a pretty good sense by how much enthusiasm he has for eating whether his appetite is good and he's getting enough to eat. He should start cracking seed or eating tiny pellets around now. I highly recommend adding tiny pellets (not seed) to his formula, adding texture and making it a bit "chunky". He should enjoy this and it's a perfect way to start weaning him onto a healthy pellet based diet rather than a seed based diet. Seeds definitely have their place in a tiels' adult diet but unless you start very early with pellets you may have a hard time getting him to eat pellets after he's warned onto a primarily seed diet. I can't emphasize enough how important it is to start feeding him healthy foods like pellets and finely chopped fresh veggies and fruits while he is weaning. It will set him up for a lifetime of healthy eating habits instead of a seed only diet which is so bad for parrots, including cockatiels and budgies (they are small parrots). Rocky associated me with "good food" so much as a chick that all I had to do to get her to eat something new was to show her I was eating it myself with lots of gusto! The hard part now is keeping her out of our plates during meals because if we are eating it, she wants it too! If I'm eating something healthy for her I chop some up really fine and give her some in her food bowl (though she prefers what's on our plates) She loves scrambled eggs, pasta, rice, sweet red and green peppers, chopped dark greens like spinach, kernel corn, rolled oats, unsalted crackers. She even likes bits of well cooked chicken and tuna. I have to stop her from eating some foods that are too salty and cheese is only okay in tiny amounts. Others may add some of their comments and id I'm feeding Rocky something I shouldn't, please tell me!