I've noticed a ring of this white area around Goliath's shell - just realised it's calcium from his soak water! It wipes off easily and is a ring right round where the water level comes to. We have very hard water here.Dozer is 3 years old and 10 lbs. Yesterday I notices these faded areas on his shell. I touched it with my nail and it scratched easily. Fungus? If so, which antifungal is advised?