10 Best Aquarium Auto Top-Off Systems Worth Your Money

Keeping fish is a fun-filled activity but requires necessary maintenance.

Having to check whether the level of water has declined since the evaporative tendency of water takes its tool could lay a burden on aquarists. However, with an auto top-off system, measuring the water level and filling (if needed) will be implemented automatically – with little or no interference.

In this post, we’ll introduce some options available when it comes to selecting the best aquarium auto top-off systems for your tank. You also learn some tips to choose the right system for your setup.

What is an Aquarium Auto Top-Off System?

An auto top-off system is an incredible device that automatically identifies the water level in your reef tank, then automatically replaces the lost water, making sure the water turns back to the proper level.

It saves you from this tiring daily chore because it can take enormous effort lifting buckets of water and wiping down spills. Thereby, the salinity is maintained steady, so your fish stay healthy. Plus, this system also helps protect your pumps from running dry.

Tips on Choosing The Right Aquarium Auto Top-Off System

When it comes to picking your auto top-off system, there is no one-size-fits-all option. However, you can leverage this guide to find out which system works for your setup and which specific features you want.

Sensor

There are some types of sensors available on the market.

Float Switch

This is the original sensor at an affordable price, with a simple and effective working mechanism.

A Float Switch sensor employs a buoyant magnet to open and close the circuit when your water level has changed.

The drawback is, that they’re likely to get stuck.

Small marine creatures, such as snails, can get on your float and stop it from checking your water level accurately. Besides, algae and calcium buildup might stop the float from moving, causing it to fail. Plus, any other surroundings could interfere as it’s a magnet.

However, don’t be too depressed. Most modern models have given solutions to these problems, like employing plastic shields or backup float switches to minimize failures.

Optical Sensor

Less inclined to wrong readings or failure as it contains no moving parts, this is a prism-shaped water level sensor.

In case there is no liquid, an infrared LED light is shot via a prism into a light receiver to start the pump.

When your water level has increased, the light cannot reach the sensor, shutting off the pump.

Temperature Sensor

Including no moving parts, auto top-off systems with temperature sensors are often smaller than the others.

When you submerge the probe, it will cool the sensor, when your water level decreases below the probe, it will heat up to activate the pump.

Conductivity Sensor

A conductivity sensor utilizes 2 probes which are determined at the standard water level. An electric circuit will be created instantly as the probes enter the water to deactivate the pump. Meanwhile, if the water goes below those standard lines, that circuit will be broken immediately to start the pump.

The conductivity sensor is built without moving parts to prevent the chance of failure.

The Reservoir’s Size

You will use the reservoir to store the water for topping off your aquarium.

Most aquarists use 5-gallon plastic jugs or buckets as they are cheap and easy to handle. If you don’t want to use a bucket or jug, you could use a custom acrylic or glass container. Just ensure your pump fits into the container.

The pump

This is another essential piece of equipment that will transfer water from your reservoir to your aquarium.

Some auto top-off systems are packed with one; some don’t.

You’ll have two options when choosing pumps: dosing and submersible.

With a dosing pump, you won’t face the risk of a dry-run or pumping water at a slow rate. The pump helps make your tank safer as it won’t overflow your setup if you fail.

Dosing pumps are not submersible, so you have to hang them above your reservoir.

Meanwhile, submersible pumps turn out to be an easy-to-use and budget-friendly option, quickly delivering water into your fish tank. However, the downside is that they pump water fast, so you have less time to react before your aquarium overflows in the case of a failure.

List of Best Aquarium Auto Top-Off Systems

1. Smart ATO Micro Automatic Top-Off System

Smart ATO Micro has a weight of 12 ounces and dimensions of 2.8 x 6.3 x 6.5 inches. The device takes advantage of Quick Security Technology (QTS) to minimize the chance of failure.

This product uses an optical sensor to enhance accuracy. What you need to do is to use that sensor to determine the standard level of water. The pump will instantly work as it gets a signal from the sensor.

The selling point of the Smart ATO Micro is the complete kit. You’ll find no need to buy any accessories as all required items are included in the package. The box provides you with a magnetic holder, a controller, power adapter, and tubing.

Moreover, the model does not have any moving parts, so you can install the entire system easily. Plus, the amount is magnetic, so it will make the setup simpler, saving you a lot of time and effort.

Pros

• Lightweight
• Utilize Quick Security Technology to prevent failure
• Well detect the levels of water
• Easy to use and set up
• Provide a full 24-month warranty

Cons

• Not ideal for big reef tanks
• Not provide a robust magnetic holder
• Regular maintenance required

2. Tunze 3155.000 Auto Top Off System

Tunze USA LLC has been one of the most well-known brands in this industry since it was established in 1985.

This is a compact and lightweight product, with a weight of 2 pounds and the dimensions of 4 x 1 x 2.5 inches, taking up less room than the Smart ATO Micro.

This Tunze system makes use of 2 types of sensors which are float switch and optical sensor. Both will work together to ensure that the model can check the levels of water and give a precise result.

The product comes equipped with a full kit, so you do not have to purchase additional accessories to make the system work. There are also magnetic mounts, which will be helpful for those who don’ get on well with technical products.

Pros

• A well-made item from a famous brand in the industry
• Small and compact design
• Easy to use and set up
• Excellently read the levels of water and refill your aquarium

Cons

• Quite pricey
• Frequent maintenance required

3. Tunze USA 3152.000 Automatic Top Off Nano Osmolator

This is another product of the Tunze brand. The model is very light, at only 1.7 pounds only, and does not require too much room (1.5 x 1.2 x 1 inch).

The unit uses 2 sensors – a float switch and an optical sensor to keep the ideal water levels for your tank. In addition, the device is easy to install and can be positioned on the tank edge or in a filter. You will not face any difficulties, thanks to the magnetic holder.

The selling point to the Tunze 3152.000 Auto Top Off System is that it requires low energy to run. The system runs quietly, without disturbing your activities.

Pros

• Lightweight and compact
• Energy-effective
• Simple to install and use
• Silent operation

Cons

• Does not have a good performance on larger tanks

4. Hydor Smart Level Controller 

This Hydor Auto Top Off System is well-known for its energy saving. It is lightweight and compact, with a weight of 14 ounces and a measurement of 5.5 x 1 x 2.5 inches.

Notably, the device can work in various environments, including freshwater or saltwater aquariums. Its structure is strong enough to avoid being covered with rust.

The unit can detect the evaporated water and activate the pump to transfer water to the tank in time. Especially, it can distinguish between the water movements and the real levels of water, which helps prevent the excess amount or shortage of water.

With both manual and instruction videos, you can understand the device’s operation and structure in a few minutes.

Pros

• Energy efficiency
• Lightweight design
• Well adapt to different environments
• Inform users about errors with the dual alarm

Cons

• The sound alarm sometimes might cause annoyance.
• The pump is relatively weak for a large tank.

5. EptTech Marine Reef Aquarium Auto Top Off System 

The EptTech unit provides everything necessary for your setup and installation, including a hose, hose holder, pump, power supply, and controller.

With a magnetic suction cup, you can easily attach the device to the side of the tank. That means you can have control over where the sensors are. Make sure that the glass is clear and clean, or it might interfere with the sensors. The sensors are mini optical, infrared ones for absolutely accurate regulation. It will check or fill on a frequent basis.

Importantly, this auto top off system is built with incredible feedback security technology, ensuring real-time protection from malfunctions and failures.

There are two LED lights warning failures: a blue and a red light. The blue light shows that there has been a non-filling period, while the red signifies that an overflow has happened in the system. As soon as the lights inform you, you can immediately check the product for malfunctions.

Pros

• Compact design
• Provide everything needed for setup and installation
• Give users control to cover the sensors’ position
• Feature auto feedback security technology
• No cable in the fish tank

Cons

• The included instruction might be a bit difficult to understand.
• The magnetic suction cup might wear down and expose the iron core.

6. XP Aqua Aquarium Auto Top Off System 

This is the world’s first four-sensor auto top-off system, making it stand out from the competition.

The first sensor is used for top-off detection, detecting the water level and when the pump requires to be activated. The next two sensors bring a dual-stage overfill alarm with smart QST programming. And the last sensor is aimed for run-dry protection, preventing the pump from being damaged. The excellent combination of the four sensors gives you an extremely accurate water level control.

If you have a bigger tank requiring a larger pump, there is a socket switch that can run a pump up to 10A. In addition, you also receive a solenoid valve for tanks that are topped off directly with an RO/DI system.

Pros

• 4 incredible sensors
• Versatile installation with accessories included
• Efficient DC pump
• Easy installation
• No programming or adjustments required
• A socket switch for use with AC pumps
• A solenoid valve for use with an RO/DI system

Cons

• Quite high price

7. JBJ Automatic Top Off Water Level Controller

The JBJ auto top-off system is built with a wide range of features. It’s designed to replenish the water to your aquarium or sump automatically when it detects evaporation.

The device comes equipped with two float sensors that are activated within seconds if your water level declines. Additionally, its electronic controllers enable two different modes of operation with a total of three setup scenarios.

The LED indicators are highly visible, allowing you to read the display without turning on the light.

Pros

• Three-minute timeout feature
• Include two mounting brackets and two float sensors
• Easy-to-read display

Cons

• Might cause sump pumps to be dry

8. IceCap Dual Optical ATO 

This is another auto top-off system option worth considering.

The unit is to track evaporated water and replenish it every day. Therefore, you don’t need to add water manually to keep the water stable.

The device comes with a fail-safe design using two optical sensors that will monitor the water levels of the sump or tank. Moreover, the second sensor can offer real-time monitoring and protection if the first sensor doesn’t work.

Safety The IceCap auto top-off system warns you when your top-off reservoir becomes dangerously low to save the water pump from running dry. Besides, there’s a bright LED indicator that enables you to visually see the status of the device and notice any possible problems.

Best of all, it is super simple to install and includes no moving parts.

Pros

• Dual-optical sensors
• Compact design
• Plug-and play installation
• Integrated fail-safe

Cons

• Might be set off by some fish
• Include a very bright LED that is not proper for bedrooms

9. Aquarium Triple Sensor Auto Top Off Water Filler 

The next participant on the list of the best auto top-off system is this Aquarium Triple Sensor system.

The device features three sensors, so you don’t need to worry about mistakes and failures. The optical level sensor keeps track of water levels and determines whether it needs replenishing. In addition, the S1 sensor will help avoid overflow, and the S3 sensor identifies a shortage of water anywhere within the system.

There are also an alarm and multiple status indicators to prevent any errors. For instance, indications are packed for a missing overflow sensor and pump. In case something goes abnormal, the buzzer will sound and the LED will light up.

What’s more, this unit is an all-in-one system consisting of a power adapter, tube holder, controller, and refill pump. Besides, the package brings you a PVC tube, three sensors, and a magnetic base.

Pros

• Alarm for any problem
• Provide necessary accessories
• Include three sensors, to prevent any mistake

Cons

• The instructions might be a bit confusing.

10. Coral Box Auto Top Off Magnet Mount Pump

The Coral Box N50 product is a cost-effective solution for maintaining the water level of your fish tank.

The device operates using a high-grade magnetic float switch. This float switch will start the include a low pump if the water level declines while shutting it off when the float reaches your wanted water level.

You can use the unit for both freshwater and saltwater aquariums. For those who travel a lot, they don’t have to worry as the Coral Box auto top off system will keep your tank salinity and water level on the go. This makes your aquarium more stable and saves the HOB skimmers and filters from drawing in the air because of a low water level.

Pros

• Solid construction
• Highly sensitive float to prevent flooding
• Provide a pump and brackets

Cons

• The float might be fragile and damaged in shipment.
• No siphone break included

Quick Compare of Best Auto Top-Off System

#	Product Name	Image	Price	Action
1	Smart ATO Micro Automatic Top-Off System		$$	Buy on Amazon!
2	Tunze 3155.000 Auto Top Off System		$$	Buy on Amazon!
3	Tunze USA 3152.000 Automatic Top Off Nano Osmolator		$$	Buy on Amazon!
4	Hydor Smart Level Controller		$$	Buy on Amazon!
5	EptTech Marine Reef Aquarium Auto Top Off System		$$	Buy on Amazon!
6	XP Aqua Aquarium Auto Top Off System		$$	Buy on Amazon!
7	JBJ Automatic Top Off Water Level Controller		$	Buy on Amazon!
8	IceCap Dual Optical ATO		$	Buy on Amazon!
9	Aquarium Triple Sensor Auto Top Off Water Filler		$$	Buy on Amazon!
10	Coral Box Auto Top Off Magnet Mount Pump			Buy on Amazon!

An aquarium auto top-off system might not be of absolute importance for your fish tank, but it can save a lot amount of time and hassle. With a proper auto top-off system, you can comfortably enjoy your fish tank without worrying about the water level.

Make sure you spend time considering the right auto top-off system for your setup. Remember to look into the details and weigh the pros and cons carefully before going to a buying decision. We hope that this article can make it easier for you to choose an ideal product.

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