You can delete stratum by clicking on the stratum’s menu button and selecting [Edit stratum]. In the bottom left corner, you will find a red button [Destroy]. When you click on it, the system will destroy stratum and you won’t be able to use it anymore. Do note that this action is irreversible. You will lose the stratum address and even if you create the exact same stratum once again, you won’t receive the same stratum address as before.