Hydroponic systems usually include an air pump and a water pump that, respectively, aerate your nutrient solution and push it through your growing containers. Most are set to run on timers. Others use sensors that monitor the system and issue alerts.
All of this activity does, indeed, make a great deal of sound. There are gurgles, flushes, beeps, ticks, drips, hums and growls. Basically the bigger your system is, the more noise it will likely make.
But are they really loud? Or are they just white noise that fades into the background? For most cases, we say, no, they are not very loud. If your system is behind a closed door, you probably won’t notice it. When you’re in the same room, it will be a constant companion.
Our advice? Set up in an out of the way room and close the door.