Ahhhh, good for you and better still for Ocean! People don't realize how stressful and traumatic clipping is to a bird! They think of it as a solution when, in reality, they are making things worse for the animal...
Don't stress Irwin out by weighing him. I also would not bother weighing its food. All you have to do is look at the amount (and 'quality'] of poop he is producing, if it's a normal amount and quality, he is eating enough and not that sick. And, if you could grab him once a month of so and feel his chest, it should be enough to let you know how he is doing in terms of weight but don't worry if you can't. Just keep your eye on him. Birds will, just like people, feel under the weather a bit on occasion but, usually and also just like people, they fight whatever it is that makes them feel like that on their own. If you see anything out of the ordinary or if he continues to look 'down', give him antibiotics in his water. You can get doxy and even baytril for birds online
http://www.allbirdproducts.com/bird_medication.html