OK, first off, i woke up this morning and went to turn on the light in my 10 gallon, when i looked in, i was surprised at what i saw. my six cardinal tetras had lost there red stripe. every single on of them. there were six cardinals with a blue stripe and no red. is this common? second, if they breed would the babies be safe with six small cherry shrimp, or should i get a nursery, thnx