In aquatic biotremology, small tanks can be convenient to control substrate-borne vibration exposure for sensitivity tests. However, the dynamic response of a water-filled tank determines the stimuli to which animals are exposed. This study investigated the vibrational response of a glass tank to base excitation, emphasizing fluid coupling and tank resonances. When designing a tank, the first few bending mode frequencies of the base of an empty tank can be predicted with ~5% accuracy, but empirical corrections are needed when it is filled with water because fluid coupling lowers the mode frequencies. To inform future sensitivity tests using sinusoidal excitation, 11 sinusoidal frequencies between 10 Hz and 961 Hz were tested using an electromagnetic shaker. A 100 mm × 100 mm arena was defined for later tests, and grid measurements showed that out-of-plane vibration varied by up to 13 dB, yet averaging within grid squares reduced this to 7 dB at most frequencies. These findings guide the design of aquatic biotremology sensitivity tests and establish a baseline for assessing animal responses to substrate-borne vibrations.