Water is a very basic part of our lives. Without it, how can we fill the fish tank, am I right?
However, water also has a characteristic that can be inconvenient for us the fish keepers.
In order to ease our burden, the Auto Top Off System for Aquarium has been invented.
The auto top off can work for many types of aquariums. I’m here to present you with a list of the best auto top off system for a reef tank, saltwater, freshwater aquarium, and many other aquarium types.
Table of Contents
The 10 Best Auto Top Off Systems for Your Aquariums
There are many options on the market and it can be confusing to choose a good one for your tank. So here is a list of the 10 best auto top off systems out there.
|Pictures||ATO Systems||Sensor Types||Links|
|Tunze 3155.000 Osmolator Auto Top Off System||Optical Sensor|
|AutoAqua Smart ATO Micro Automatic Top Off System||Optical Sensor|
|Tunze USA 3152.000 Automatic Top off Nano Osmolator||Optical Sensor|
|Hydor Smart Level Controller||Temperature|
|XP Aqua Duetto Dual-Sensor Complete Aquarium Auto Top Off ATO||Optical Sensor|
|JBJ Automatic Top Off Water Level Controller for Aquarium||Float Sensors|
|IceCap Dual Optical ATO Auto Top Off Controller||Optical Sensors|
|Aquarium Triple Sensor Auto Top Off Water Filler||Optical Sensor|
|Coral Box Auto Top Off Magnet Mount Pump Included N50||Magnetic Float Switch|
|EPTTECH Aquarium Marine Reef Fish Tank Automatic Auto Top Off Water||Optical Sensor|
Auto Top Off System Reviews
1. Tunze 3155.000 Osmolator Auto Top Off System
Tunze is a company that has been producing top off systems since 1985. They are on top of their games. The 3155 Tunze Osmolator is the gold standard of the auto top off system world.
The Osmolator is secure and reliable. It is a product that has been tested and built through the course of many years and many previous models. The Osmolator is small with a size of 4x1x2.5 inches and it weighs less than 3 pounds. It is one single compact unit.
The Osmolator uses a set of two sensors to detect the water level. The primary sensor is a mini optical infrared sensor which can provide highly precise regulation. The second sensor is a float sensor, which serves as a backup sensor to feel the water level.
The Osmolator is easy to set up. The device comes with magnetic mounts for easy and convenient installation. It comes with a full package of tubing, pump, and power supply. It does not only recognize the dropping level of water but also effectively pump water from your external source into the tank.
This product is one of the top-notch products on the market. That’s why it can be a bit more pricey compared to other products. The price is a little high for an auto top off system. However, you know that you will get what you pay for, so the pricey tag, in this case, will not disappoint you about the product’s quality.
- High-quality build
- Small in size
- Easy Installation
- Precise estimation of water level
2. AutoAqua Smart ATO Micro Automatic Top Off System
The AutoAqua system is one of the most highly rated Auto Top off systems in the market. The system is small with a size of 2.8 x 6.3 x 6.5 inches and weighs only 12 ounces.
This product includes an advanced technology called Quick Security Technology (QST). It is a contactless digital sensor. This technology acts as a sensor to continuously provide real-time fail-safe protection against failure.
The technology is designed to make it not only convenient but also very reliable. You can simply move the optical sensor to adjust the desired water level of your tank and whenever the sensor senses that the water level drops below the desired mark, the pump will be activated to automatically refill the tank. Your fish and plants will stay happily in a water-filled tank.
The unit is very easy to install. It contains no moving parts that can cause you any troubles while installing as well as when using. The device comes with a controller, sensor, power adapter, tubing, and mount. The device is ready to go right out of the box and the mount is also magnetic, making the setup even more convenient.
The problem with this system is the pump that comes with the device. Some people complained that the pump can be a bit weak for their tanks, while others found that it worked fine. It all depends on the size of the tanks. If you happen to have a tank bigger than the capability of the pump, you can purchase an external pump to substitute the one in the box out.
- Easy installation and usage
- Small and convenient size
- Quick Security Technology with contactless sensor
- 2-year warranty
- Weak included pump
3. Tunze USA 3152.000 Automatic Top Off Nano Osmolator
This is another product of the Tunze company. As said earlier, Tunze has been producing Auto Top off systems since 1985 and they have made themselves a reputation in the market. The Tunze 3152 system is one of their two best-selling auto top off systems.
This model is small with a size of only 1.5 x 1.2 x 1 inches and weighs less than 2 pounds. It can be installed in a cabinet filter or directly on the aquarium edge. The mount/holder is magnetic, making it easy to install and it can mount over the glass wall up to 3/8 inches thick.
The device comes with two sensors. The primary one is a mini optical infrared sensor which can provide precise regulation of the water level. There is also a backup sensor that floats on the water. The two-layer of sensors makes the system fail-proof and keep the quality of the whole system consistent.
The device is very energy efficient. It works with only an 11V power supply and the pump is also low-voltage. It also runs reasonably quiet so you don’t have to worry about the noise of the system disturbing people around.
This device is very small and convenient and there is a trade-off for that size. This auto top off system can only work efficiently with the tank the size up to 55 gallons. It can work in bigger tanks, but the quality is not efficient enough for the whole tank, and failure can happen.
If your tank is smaller than 55 gallons, this device is still a very good choice since its price is much cheaper than its brother who can work in bigger tanks.
- High-quality build
- Small and convenient price
- Easy installation
- Work efficiently in tanks up to 55 gallons only
4. Hydor Smart Level Controller
The device is 5.5 x 1 x 2.5 inches and weighs about 14 ounces. It is low voltage and very energy efficient. It is designed to be used in many different conditions, including both marine and freshwater aquariums. The quality of build is superb, helping the device to resist rust in both fresh and saltwater.
The device comes with a dual alarm system that has both light and sound. It will alert when the water level drops below the desired level and it will also alert you if there is any malfunctioning with the device itself.
The sensor is designed to not only be functional but also ‘smart’. The sensor of the device will recognize the water level and alarm you when the water level drops. The device will automatically activate the included pump to fill the tank with water.
This system is also capable of differentiating between actual water level and movements of waves. Thanks to this functionality, the tank will not be filled and you will not be alerted by mistake.
As convenient as the alarm system, it can be annoying to some people. The audible alarm system can ring at random times during the day and it can bring some annoyance and inconvenience. With the double alarm system, you cannot turn off one of the two alarms.
The pump works well. However, it is a pump included in the package so it’s safe to say the pump is not the highest quality. If you have a big tank, you can always purchase an external pump and switch it out for bigger capability.
- Easy installation
- Energy efficient
- Dual alarm system
- Smart sensor system
- Cannot turn off the audio alarm
- The pump may not be strong enough for big tanks
5. XP Aqua Duetto Dual-Sensor Complete Aquarium Auto Top Off ATO
Those who want something easy to use are going to like the XP Aqua Auto Top Off ATO. It features the smallest ATO sensor anywhere in the world. Plus, it provides you two layers of overfill protection for your home’s safety.
The programming is intelligent, which means it senses when it should turn on and off. You really don’t have to do anything but plug it in and let it start working. Along with that, the sensors will work in the dark, so you don’t have to keep the lights on.
There is a secondary sensor, which helps to protect your home from flooding. The water level controls are highly precise. Therefore, you don’t have to worry about it not sensing that there is plenty of water already.
Most people are going to enjoy the fact that they don’t have to program or adjust the product before using it. Just set up the sensors correctly and plug it in. You also receive all of the installation parts needed, as well as a magnetic coupling.
- Two-layer protection from overfill
- Highly precise controls for water level
- Plug-and-play installation
- Malfunctioning sensors a possibility
- No automatic shut-off for dry pumps
6. JBJ Automatic Top Off Water Level Controller for Aquarium
The JBJ Automatic Top Off Water Level Controller has a variety of features. It’s designed to replenish the water to your tank or sump automatically when it senses evaporation. You also get two mounting brackets and two float sensors.
Your goal here is to keep the pumps from running dry. This product does it accurately for the most part. There can be times where the sump goes dry during water changes, so be aware of this issue.
When the pump is operating, you will hear alert signals. It’s a normal thing, but the noises aren’t extremely loud.
The LED indicators are highly visible, as well. This means you can read the display regardless of the time. You won’t have to turn on the lights if it is dark in the room.
Its float sensors are designed to activate themselves automatically. This happens within seconds of the water level drop. Therefore, you don’t have to worry about too much water being lost from your tank, and it will refill it to your desired point.
- Three-minute timeout feature
- Bracket system included for sensors
- Easy-to-read display
- Might stop power to the pump for too long
- Can cause sump pumps to go dry
7. IceCap Dual Optical ATO Auto Top Off Controller
An Auto-top-off (ATO) system is one of the most important parts of your saltwater aquarium. Therefore, you need to ensure that you have chosen the best. The IceCap Dual Optical ATO Auto Top Off Controller is ideal.
It is designed to monitor for evaporated water and replenish it each day. That way, you don’t have to add water manually to keep the water stable.
This ATO is a well-thought-out system that’s all automated. It also includes a fail-safe design using two optical sensors. They monitor the water levels of the sump and/or aquarium.
Typically, the second sensor is there to provide real-time monitoring and protection in case the first sensor fails. There are no moving parts with this system, which prevents failure.
If your top-off reservoir gets too low, the device will alert you so that your sump/aquarium doesn’t run dry. Plus, it’s easy to install. You don’t have to be a professional plumber or electrician to plug it in and mount the sensors.
- Dual-optical sensors
- Compact design
- Integrated fail-safe
- Plug-and-play installation
- Includes the pump
- Can be set off by certain fish
- Very bright LED; not ideal for bedrooms
- Kinked tubing from sitting in package; soak in warm water to soften
8. Aquarium Triple Sensor Auto Top Off Water Filler
The Aquarium Triple Sensor Auto Top Off Water Filler is an ideal solution for your tank. This smart water-replenishing device meets the needs of those who do not want to refill their tanks all the time because of evaporation.
There are three sensors included, so you never have to worry about mistakes. The optical level sensor monitors water levels and determines if it needs to be replenished. Plus, the S1 sensor will prevent overflow, while the S3 sensor monitors for a shortage of water anywhere within the system.
You’ll also find an alarm and various status indicators to prevent errors. For example, indications are included for a missing overflow sensor and pump. If there’s an abnormal situation that occurred, the buzzer will sound, and the LED will light up.
This product features an all-in-one system. The package includes a power adapter, controller, tube holder, and refill pump. Plus, you also get a PVC tube, three sensors, and a magnetic base.
Though you do have to install the product, it is quite easy to do so. The instructions are clear and concise. Plus, you don’t have to adjust or program the product before you start using it.
- Alarm for any issues
- Magnetic sensors stay where placed
- Three sensors included
- Confusing instructions
- Design flaws for optical sensor and float valve placement
9. Coral Box Auto Top Off Magnet Mount Pump Included N50
When you want an affordable solution to maintain the water levels of your aquarium, the Coral Box Auto Top Off N50 is ideal.
It features a magnetic float switch, which is made of high-quality materials. This activates the pump when your water level drops.
The included pump is an excellent addition. Plus, the ATO will shut off the pump when the float is at the ideal water level. You don’t have to program anything; just install the float where you want the water levels on your tank.
This product is ideal for freshwater and saltwater tanks. Those who travel often will find that an ATO allows you to leave without fear of flooding your space or running the tank/sump dry.
Plus, you will find that the auto-top off prevents your filter or skimmer from drawing in the air because of low water levels.
If that weren’t enough, you can use this product with any size aquarium, making it ideal for all people and spaces. It also features a pump with a head height of up to six feet.
- Solid construction
- Extremely sensitive float (prevents flooding)
- Pump Included
- Magnetic mounting somewhat weak
- Randomly activated float switches
10. EPTTECH Aquarium Marine Reef Fish Tank Automatic Auto Top Off Water
When you purchase the EPTTECH Auto Top Off Water, you get everything you require.
This includes the pump, ATO controller, power supply (plug), a hose holder, and the hose itself. Therefore, you will not have to go out and buy a new pump.
As with some ATOs, the cabling is so big or long that it gets into the fish tank. This can cause significant problems with time. However, this product doesn’t have that problem.
The magnetic installation makes it a breeze to attach to your tank or aquarium. Plus, you can put the sensors wherever you need them most. One thing to consider is that the place where the ATO will be installed should be clean and transparent.
You’ll find that this product features AFS (Auto Feedback Security) technology. It’s a safety feature to ensure real-time protection from failures. There are two alerts available, including a red and blue LED.
The blue light indicates that there has been a non-filling period that is double the time from the last refilling. Red LEDs are there to show that there has been an overflow somewhere in the system.
- Well-built unit
- Small pump (included) works well
- Compact design
- Magnetic parts can rupture and expose iron core
- Redesign needed for tube holder for ideal fit
- Hard-to-understand instructions
What is an Auto Top Off System?
Water evaporates at any temperature. For keeping a fish tank or an aquatic aquarium, this characteristic of water can be troublesome. There will be less and less of water in your tank each day.
And when the water drops too low, it can cause a severe problem for your fish and aquatic plants. In order to save fish keepers from this problem, the auto top off (ATO) system has been invented for everyone’s best convenience.
An auto top off system is a system designed to automatically detects the water level in your tank with a sensor. Whenever the sensor senses that the water level drop below a certain point, the system will automatically replace the evaporated water so the water level in the tank can go back to the optimal level.
Without this system, you may have to carry a bucket of water, pour into the tank, and wipe down spills. Having to do that almost every day can be quite a chore. But with an auto top off system, you will not have to do all those things. The salinity is also kept stable with the system. The auto top off system will maintain your pump from running dry.
The auto top off system is not only useful for your everyday life maintaining your fish tank, but it is also especially useful when you are out of the house on a vacation. You can set an automatic fish feeder all you want when you are away on your trip, but it won’t do as much for your fish if you come back to a tank all evaporated without any water left.
The auto top off system will take care of refilling the tank with water and not let the tank dry out and destroying the living environment of your fish and aquatic plants.
What is the Best Auto Top Off System?
When choosing the best auto top off system for you and your tank, consider some of the followings:
What is Included in the Package?
Normally, the basic kit of a package of an auto top off system would include a self-leveling controller, one or two sensors, and mounting implements.
Sometimes the complete package will also include a pump and hoses. The pump is an accessory you need to pay attention to. If you already have a pump with you, then you don’t need the included pump in the package.
But if you do not have one already, choosing a complete package with one included can save you a lot of time setting up the system in the beginning.
How is the Installation Process?
Do you mind getting all handsy and complicated during the installation process?
If you are a crafty person then you may not worry about what your choice is for this step, because you can do it all. However, if you are not the most crafty person ever, opting for something easy to install and set up in your tank can help you save lots of energy and effort. Many systems come with magnetic mounts. They are very easy and simple to install.
What is the Size of Your Tank?
Most of the time the auto top off system does not take the size of the tank into account. However, the pumps do.
So check the pumps of the system or the pumps you already have, see what their capabilities are. If the pumps are too weak, it will take the tank very long to be refilled.
What is your Budget?
As with buying anything, you need to consider your budget. There are quite a few other accessories you need to buy for your fish tank so don’t let the auto top off system uses up all your budget. Choose one that you can afford comfortably.
How to Set Up an Auto Top off System?
1. Take all your supplies out of the box. Before installing anything, power all the units up and test the sensors and the pump to see if they work. If there are sounds or light alarm, check to make sure they work probably as well. It is much easier to test the device now than having to take them out of the tank later because they don’t work right.
2. Just prepare an empty reservoir. Do not fill it with water yet. It is safer and easier to work with an empty reservoir during the setup.
3. Prepare a freshwater reservoir by the side of your tank. It can be a bucket or a big jug. The smaller the opening is the better with the reservoir since it is harder for water to evaporate and you will not have to change the reservoir as often. I recommend using a jug with a small lid, similar to a gas can. Drill or cut a hole in the lid, big enough for the tubing to go through later. With the lid closed, the exposed water surface is limited and therefore limited to a minimum the evaporation of water from the reservoir.
4. There would be two sensors with the device. They need to be floating in water in order for the whole unit to work right. Place one in the freshwater reservoir. The other one should be installed in the sump just above the waterline. Sometimes, some devices come with special or smart sensors that work differently from the other common sensors. If that is the case, make sure to read the included manual carefully to set them up correctly. The sensors are the most important part of the whole system.
5. Get ready to install the pump. There should be two outlets in the pump: the ‘in’ and the ‘out.’ Run tubing from the freshwater reservoir to the ‘in’ on the pump. Then run another tubing from the ‘out’ on the pump to the sump. Try to make the tubing stay above the waterline when installing the ‘out’ tubing. When the tubing is underwater, it is possible to create a back siphon and that can accidentally suck up all the water from the tank to the reservoir, which is the opposite of what we want to do with the system.
6. Plug the device into the outlet. Make sure your hands are dry when plugging in the device. Also, make sure there is no water close to the outlet. It can be dangerous so it does not hurt to double-check.
7. Finally, fill up the freshwater reservoir and your auto top off system is ready to go.
Video set up an auto top off system for reef tank
An auto top off system is not an absolute accessory for your tank but it is such a convenient and useful one. With an auto top off system, you will almost never have to worry about your tank whenever you are away from the house for a long time anymore.
If you are looking to purchase an ATO system, make sure to do your research and answer for yourself all the questions I stated earlier in the ‘What is the best auto top off system?’ section. You can also read people’s reviews and comments about the products online to understand more about the product’s quality, strengths, and weaknesses.
Make sure when you buy one, you are happy with your choice. And a good quality, functional ATO system will ease your mind and keep your fish and plants happy and healthy in their tank.
Related Buyer’s Guides and Aquarium Adviser Lists:
Best Aquarium WaveMaker for Saltwater Marine, Reef, or Fish Tanks
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