No, fiberglass pools should never be drained without proper bracing and under the supervision of professionals. The structure of a fiberglass pool relies on the support provided by the water inside it. Draining the pool completely without the necessary precautions can lead to structural damage, including cracking or even collapsing of the pool shell. It is essential to consult with a qualified pool contractor or technician who can guide you through the proper procedure for draining a fiberglass pool, ensuring the necessary support and safety measures are in place.