Ranchu Weigh-In

I bought an Ozeri kitchen scale ($18.85 on eBay) recently to weigh my ranchu's and track their dietary progress. Bumblez (sakura ranchu) weighed 31 grams and after 2 weeks he now weighs 31.5 grams (0.5 gram gain); Oakki (black metallic ranchu) weighed 28.5 grams and after 2 weeks he now weighs 33.5 grams (5 gram gain). I'm hoping Bumblez isn't sick or anything, he seems to eat but perhaps is just a slow and picky eater (compared to Oakki whom gobbles down everything).

Scale showing 2 different weights during this weigh-in.

Oakki has grown so much that my dad actually thought I had bought a new fish! Perhaps Oakki is just having some type of growth spurt, I have heard that fish with more hormones tend to grow more rapidly.