Can I use my propane tank from grill on a turkey fryer?

No.

Propane tanks used for grills are not intended for use with turkey fryers because the burner on a turkey fryer is less efficient than the burner on a grill. This means that more fuel is used, which can lead to a dangerous build-up of pressure inside the tank and cause an explosion. Additionally, propane tanks for grills are not designed to withstand the high heat generated by turkey fryers, which can cause the tank to rupture and release flammable gas.