I bought this for my 40 gallon reservoir, I obviously bought bigger than necessary. It maintains temperature well, it does take longer than expected to chill there water from around 74 degrees, down 63 degrees. I am glad I bought bigger for that reason, I usually throw some ice in to help it chill quicker. All in all it is the best purchase I made for my setup, I just wish it worked quicker, but I worked around it. Unit does generate an decent amount of heat, so make sure you place the unit in a space you don't mind it heating up. I'd say noise is comparable to a portable ac unit, dehumidifier, any small appliances like that, you can hear it when next to it, but wouldn't keep you awake.
N Nana 
