The system itself will make noise.If I listen hard enough,I can hear the skimmer,return pumps and especially the cooling fans on the light fixture since it's not under the stand to muffle the sound.It all sounded kinda loud at first but I got use to it.There are somethings you can do like choosing equipment.Some pumps are louder than others,having a submersible pump are generally quieter than in-line pumps and although not as attractive,vinyl tubing quiets the noise of water running through the system better than pvc plumbing.