I have about 30 guppy fry in a 10 gallon tank. They are about 4 months old, but still only about a half an inch long. i feed them 3 times a day: brine shrimp in the morning, and adult flake food in the afternoon and night. Their water temperature is around 80 degrees during the day and 78 degrees at night. I looked at some of the pictures of 4 month old guppies online and they are definately a lot bigger than mine. Why are they so tiny still? Could it have something to do with the fact that 30 of them are in a 10 gallon tank, or does that not affect it as much as something else?