I used a chick drinker with marbles for them to peck at. A shallow dish may lead to drowning, since new poults are incredibly clumsy. It is like they can't control their uber long legs very well until they are older.
We have 40 turkeys with average age of four weeks. We used quart chick waterers for first two weeks then moved up to gallon size. We did not do marble trick our silly turkeys were afraid. I think a shallow bowl or dish is not a great idea as the will either step in it making it unsanitary or spill making their bedding too wet and yes from what we have learned they can drown or suck I water causing pneumonia.
i used a quart size waterer with marbles in for the first week or so. You want to make sure you show them the water and the food. My first hatchling almost died because i though the baby chicks would show him.