I took a look at your video, and hate to say it but that Sebae (( H. crispa )) is in pretty poor condition. Besides being bleached (( white )), its mouth is slightly open, and lastly its tentacles are too short -- meaning that it is most likely been consuming itself for energy.
What are your water parameters (( with numbers )) and what lights do you have?
Lastly, a healthy Crispa will out grow that tank is short order.