I built a huge turtle farm in mc but they all die after they hatch. Do they need water to survive? I've already dug waterways, but they don't bring anything.
Turtles do not necessarily need water, but it makes sense because they like to swim in it. The water can be shallow or deep. Baby turtles die like all other creatures, they can drown too. But some should survive. Maybe the room is too small, after all the adults are not 1 block tall.
It is important that they have sand, on grass they may not survive there.
Ahem a bit embarrassing, but the floor of the turtle farm is made of basalt😬
You don't have to be embarrassed, you can't know everything. Change the ground and see what happens.
Ok, thought it goes all over the place, never bothered with the turtles
WIKI from gamepedia will always help or enter Minecraft turtles in Google.