RES : how to know they are growing?

Question
hi Amanda,
i have two Red Ear Slider turtles i got them 4 months ago they were 2 inches(5cm) long when i got them and till now they are exactly 2 inches(5cm), but their shells changed and their color too.
they became more dark green,I'm feeding them pellets and dried shrimps twice every day, they have a basking area,i give them calcium supplements.
But my RES are not growing!
if you can help me know when do they grow and how to know they are growing?
hoping you reply me soon ^_^

Answer
Shamsa,

Here is an interesting link about the documentation of the growth of a group of RES turtles.  If you are lazy, like me, just scroll down to the bottom and you can get a rough idea of their growth in a year.  

http://www.picolio.com/staticpages/index.php/TurtleGrowth

About their shell changes, I hope you don't mean that their shells are curling up around the edges.  Are you feeding pellets formulated for baby turtles?

The dark green sounds fine to me, but I'm guessing.  I'm not a slider expert.  If you want to send me a photo I'd be happy to check it out.

-Amanda