I currently have a DIY Co2 system in my 75g tank. I am considering moving to an automatic Co2 injection system. My question is, do the solenoid or any other part of the system make any substantial noise? My tank is in my family room and I'd prefer not to have any extra noise from my aquarium other than the filter and splashing of the water. I'd hate to invest in the system only to find out it annoys my wife! Thanks.