ah, thank you for understanding my friend! I have faith you will go far with such good empathy. Truly so
A DSB is a "deep sand bed" system... a popular tank or refugium strategy with say 4" + of fine substrate to get natural nitrate reduction (NNR) as well as culture different microorganisms not commonly found in coarse sand or gravel or live rock only. The hope here is that a fishless DSB refugium might generate some useful plankters to feed the hydroid. Also, the small refugium would concentrate feeding opportunities if you added food or prey like bottled or live cultured plankton. It really could be a fabulously interesting display... but is indeed going to be some work for you.
For some hobbyists this challenge is great fun, for others though it is simply a burden (extra vessels and/or live plankton culture). I frankly fall into the latter category oftentimes myself... too busy or too lazy for special needs species. While this is so, I limit my choices but still have a wide range of amazing creatures to choose from to study/enjoy
No worries... you can handle the challenge if desired, but elsewise its good to hear you are willing to look for another home for it if needed.
best of luck and life,
Anthony