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[cyclamen]

no its not normal. and its not good for them. but, i recently brought two from a place and they both have soft shell.
make sure they have calcium in therre tanks, you can buy the calicuim cubes from all good pet shops. and also, buy them a uv light or hav them outside in the sun. mine had really soft shells when i got them, and they smelled bad from it, but since i have had them, they dont smell and there shell is getting harder. but it takes many months before its good again. hope that helps
mel.