My Take on the Ice Cap Auto Top Off Unit

by | Oct 18, 2018 | Equipment, Industry | 0 comments

Auto Top Off unit. One of the most overlooked but most important parts of our hobby, this mechanism was created and has made so many reefers’ lives easier by automating the top off process, stabilizing the salinity in our reef aquarium by properly replenishing the freshwater that leaves through evaporation. It has saved me countless trips with 5 gallon homer buckets, giving me more time to just enjoy my aquarium, as well as peace of mind about leaving home for few days on a vacation without worrying about the  return pump giving out suffocating gurgling for more water. I am positive I’m not alone in this department and I feel that it’s imperative to find a good unit that works for you. As Sanjay Joshi said in our interview, buy the good product once. It will save you money and headaches down the road, and that is so true with this mechanism. These days, there are many companies that are making some great units for different applications and for this blog, I got my hands on the Icecap ATO unit, as some of my followers have been asking for my opinion on this product.

So without further ado, here we go!   

Box shows assembled units on the outside. Let’s take a look inside the box.

This unit is a plug and play and it comes with everything you need: pump, sensors, mounting accessories, and instruction booklet, as well as excess hose for your application. This is exactly what you see as soon as you open the box.


I noticed that instead of the traditional float switches, IceCap opted for optical sensors, which many companies are utilizing.  I also noticed that it has two instead of one. How does it function? I thought that the second one is for contingency purposes but wanted to confirm due to the directions of the sensors. To find out, I contacted Carlos Chacon who is the Product Development and Head of Product Support for Coralvue and he confirmed that it was indeed for a contingency plan in case of one were to ever fail. “Two sensors are better than one.  The second sensor is a backup sensor in case the first one fails.  When the first sensor is working correctly, the second sensor is dormant.” I like that, as any manmade product has the possibility of failing, and having a back up sensor give me a sense of comfort when I leave my tanks to go shoot different events, tanks, and videos.  Although I love new toys and the advancement of technology, I am still an old school reefer at heart and had some doubts about new sensor technology so I asked about that as well.

How long does this censor usually last, and do we have to do any kind of maintenance to keep it running in optimum conditions?

“The sensor can last for years as long as it is kept cleaned.  All you need to do is take a toothbrush and scrub off the head of the sensor to remove any film or gunk that may cause the sensor to fail.  Other than that, the sensor is very reliable.”

Has there been any issues? If so, can you share some tips/advices?

“No issues really.  By adding that second sensor to prevent the pump from adding too much water to the system, the ATO is very safe to use.  If you keep the sensor free of gunk, there should be no issues at all. ” 

I also liked was how everything was put together. Instead of having two sensors with magnets for each, sensors are encased in molded plastic housing that is easy to put together and easy to take apart for routine maintenance or replacement.

Now putting things together!

These are the parts to put together:

All the parts and accessories were well thought out and given ample amounts of materials for different applications; I like the simple graphic illustration approach (fancy way of saying I like pictures instead of words)  to assist not so handy people like myself. Took me just 5 minutes to put it together and install it into the tank. the inclusion of siphon break, and clips to hold the line in place was a nice touch. It’s simple yet effective and it’s the little details like this that makes all the difference in choosing one product from another if they are pretty much same in every other aspect (price, functionality, performance etc). The neodymium magnet had some depth to it and it was housed in 100% sealed plastic, which addressed my concern about magnets rusting in water. It also holds up to 1/2″ material which should be good for any type of sump or water reservoir (even for most smaller tanks that people substitute for sumps). The pump was tiny, and would fit in almost any container. It has max head pressure of 6ft and work with most applications but if you need a more powerful pump for more head pressure, you may need to look for another model.

Final take. 

Carlos said something that really resonated with me. I think this should be the way that all companies should approach consumers. “We wanted and needed something that we would feel safe running on our own systems. This required something with enough failsafes in place to prevent the inevitable product failure. Easy of installation was a must, the ATO had to be universal so that any user could install it with little effort. The device also needed to be affordable so that all aquarists can take advantage of safe water top-off.

Powered by 2 sensors with audible alarm and priced at $129.99, this ATO is something you should consider if you are in the market for an affordable and reliable unit to replenish fresh water in your aquarium. Your back will thank you- as well as your wife and your aquarium.

Happy reefing!

  • Afishionado

    Afishionado : a person who likes, knows about, and appreciates a usually fervently pursued interest or activity. (In this case, fish, corals and reef keeping). We are group of passionate hobbyists who are all about educating, creating innovative contents and providing eye popping visuals for hobbyists of all levels.

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