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  • Tunze Osmolator 3155

Tunze Osmolator Universal 3155
Auto Top Off

SKU: 202307


  • Very good product By KEITH on 4/15/14

    Tunze 3155 works as described shut off valves are the best
  • Optic sensor failed By Me on 4/15/14

    I just came home, and the water level was 2 inches low.
    Optic sensor out of the water but nothing happens.
    Worked fine for one year thats all.
  • a must By Nick on 4/14/14

    It works, its everything it is supposed to be! I love the dual level sensors and the pump is near silent. I think everyone understands they need an ATO. This is the best way to go.
  • Keep Tank Stable By Mitchel on 4/12/14

    Another great product from a great manufacturer that has been around forever. This ATO helps keep your salinity in check which helps for a better overall stable system. What else can you ask for out of a product.
  • Simply works perfectly By Eldog on 4/7/14

    Operating top off for 230 gallon reef tank with 75 gallon sump for three years now. It's truly a set it and forget it system, maintains perfect top off levels for optimum in-sump skimmer operation.
  • Fool Proof By Ryan on 4/6/14

    I'm a rookie when it comes to saltwater reefing, this unit is by far the best purchase I have made. Easy to use and definetly plug & play
  • The Best By Matt G on 4/1/14

    Easy to set up works the way it is supposed to work. I am very happy with it so far.
  • This thing is awesome. By Bill on 3/27/14

    We bought this thing for a new tank set up we are doing, but then decided to do a gravity fed replenishment tank instead, so we weren't going to use this... until the next night when the auto top off on our current system died. I pulled this one out of the box and set it up in about 20 minutes or less.. This thing is amazing.. Works perfectly right out of the box and is super easy to set up. While we are going with gravity fed on our new tank, I would recommend this to anyone that can't do gravity fed.
  • Tunze Osmolator Universal 3155 Auto Top Off By james on 3/26/14

    easy to set up works the way it is supposed to work. I am very happy with it so far. just make sure the place you put the water into the tank is higher then the container you store the water lol
  • Great ato system By Judith on 3/26/14

    I chose this system because it contains everything needed to set up. The first day the pump would turn on and fill up until the alarm sounded. After unplugging and letting sit in the sump submerged in water overnight, I replugged it in and haven't had an issue since.

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