12gal overstocking noob

[Eternia]

Hello every1
I ve been wanting a tank for 5 years and finally got one. Fluval edge 12 gallon. I wanted to know if 12 tetras (neon and glow mix) is acceptable. I also have a snail and 4 tiny shrimp.

 

[Fishie]

It might be a little overstocked but not to bad neons don't grow that big so I would think it would be okay but it is like a cube (right?)and they are actve I would get other opinions though.

 

[Eternia]

Yes it is a cube. The fish seem very happy this far. I started with 6 and added 6 more a couple days ago and they get along nicely. I've read that they can grow up to 1.2 inches with a life expectancy of 3-5 years. Is that correct? How long till they mature an max out in size?