The chicks are now 18 days old. They tripled to quadrupled in weight in just 15 days! It is truly amazing how fast they grow. Considering I have several different breeds of chickens, it make sense that they don't weight exactly the same, but they seem to all be within about 20 grams of one another. They are so flappy and jumpy now that I had to switch over to the full-size waterer because they managed to knock over the chick waterer last night (what a mess).
In addition to rapidly gaining weight, the chicks are also losing their fluffy down pretty fast too! They look quite scruffy at the moment (half-way between down and feathers).