Patti Tursi, age 11, of Des Moines, Iowa, for her question:

What made my turtle's shell go soft?

A pretty pet turtle needs to live in a small world of his own. He is not much trouble, but things must be just right for him. One thing he needs is his own private swimming pool, with a dry beach where he can enjoy just enough sunshine. He dines on a mixed diet of fresh meat and vegetables. When something is missing from his little world, he becomes sickly. If his shell becomes soft, something is missing from his diet. If his eyes become sore and running, he needs more sunshine.

Mother Nature provides all the things that turtles need in the wilds. But a pet turtle is a captive and naturally he cannot tell you what he needs to stay healthy.

His shell should be hard because it is meant to protect him from his enemies. In. the wilds, he gets the right foods to keep it in a healthy condition. A pet turtle needs bone meal and a little cod liver oil mixed with his meat. If his shell has become soft, you can help by putting a smallish lump of plaster of Paris in his water.

His body will use these ingredients to strengthen and harden his .shell. But this cannot be done in a hurry. A soft shell means that he has been suffering from malnutrition for quite a while. It will take time to repair the damage and rebuild it. So please be patient. His poor shell may be a little firmer after a week or so. In a month or two it should be hard and healthy again. However, your pet begins to feel better just as soon as you start the proper treatment.

A water turtle dines under water. If he is healthy he may need only one meal a week. But a sickly turtle may need to eat more often. The secret is to serve, him the kind of foods he eats in the wilds. He is very grateful when you catch him an earthworm. But a helping of raw hamburger is just as good for him. Besides, you can mix his bone meal and a little cod liver oil with the fresh ground meat.

For his vegetable course he enjoys a bit of lettuce or some other tender salad greenery. For dessert, you may give him a small helping of fruit. Nature serves no cooked meals so all his food should be fresh and raw. It is not wise to feed him by hand. He has no teeth but his hard bony jaws might bite you by accident.

Out in the wilds, the trash and garbage decay and change into chemicals that can be reused as plant foods. This is how nature keeps things clean and healthy. But it does not work for your captive pet. So it is up to you to do his house cleaning. After each meal, clean out his box, change his water    and remember to replace the plaster of Paris if he needed it.

A turtle spends a lot of time in the water and his private pool should be big enough for a comfortable swim. However, he also needs to dry off in the air and soak up some sunshine. He needs a rock or a small beach, just above water level so that he can scramble ashore. If his eyes get sore and runny, gently dab them with boric acid    and rearrange his small world so that he can get more sunshine.