Mystery snail shell

[Adam W]

My mystery snails shell is changing color. Should I be worried? It is still very active and looks good but the shell is almost turning translucent. I have a 75 gallon planted aquarium and I tested the water yesterday with my API master test kit. PH 7.2, ammonia .25, nitrite 0.25, and nitrate 20. I did a 25% water change after the test. Water temperature is 78. Thoughts?

[CalmedByFish]

No experience with mysteries, but after I started giving my Malaysian trumpet snails crustacean food, the new growth of their shells looked very different from the pre-food growth. So regardless of whether there's currently a problem, I can tell you that food specifically for critters with shells is really good for them. 

[xXInkedPhoenixX]

Adam, well I personally wouldn't be comfortable with the ammonia and nitrite levels- I definitely aim for zeros there. How's the water hardness? A Mystery snail's shell needs minerals/calcium- over a long period of time without it the shell will wear down and thin. You can also tell when water parameter changes have happened to your Mystery snails because they develop ridges and/or grow shell differences.