10 Best Aquarium Controllers

As aquarium sizes become larger and more refined, its surprise that the tools needed to keep them running smoothly has improved. Taking care of an aquarium is a rewarding hobby that has many responsibilities. However, these are minimized with aquarium controllers. Listed below are some of the best devices sold online, of which can serve as the nerve center of your fish tank.

Best Aquarium Controllers 2019

The following is a brief comparison of common features found on the aquarium controllers reviewed below:

ProductpH controllerTemperature ControllerAlarm
Hydor Smart Level ControllerNoNoYes
Inkbird Itc-308
(Editor's Pick)
SENEYE Reef Aquarium Monitor
(Editor's Pick)
Milwaukee pH ControllerYesNoYes
Bluelab CONTPH pH ControllerYesNoYes
American Marine PINPOINT pH MonitorYesNoYes
RISEPRO Digital pH Thermometer Temperature MonitorYesYesYes
Sequoia Aquarium ThermostatNoYesYes
Finnex Temperature Controller/Titanium TubeNoYesYes
GROWNEER LCD Digital ThermostatNoYesYes

Buyer’s Guide

Because of the variety of controllers and sometimes confusing compatibility they possess with aquariums, choosing the right item for your needs can be a daunting task. Below is a detailed list of questions that will help you retain all relevant information on the products used to keep your tank operating smoothly.

FAQ (Frequently Asked Questions)

1. How do I determine which product is best for me?

Aquarium controllers can be classified into at least four categories:

  • Spectrometers – A spectrometer measures the amount of electromagnetic radiation that is emanating from light. If your aquarium is filled with reefs and aquatic planets, it is suggested for you since they rely on photosynthetic properties to develop.
  • Temperature monitors – Most fish and water plants will not survive for long if your tank’s internal temperature is not set at the levels specified for fresh and saltwater animals to thrive. A monitor for your water’s climate will ensure that all fauna remain at healthy levels.
  • pH monitors – The salinity of your tank is important if you own freshwater and especially saltwater fish. When the acidity content of your aquarium changes, pH monitors help stabilize the alkalines in the water in tune to your predetermined specifications.
  • Bundles – These controllers will have several of the aforementioned monitors built into the device. Some of them are even compatible with automatic feeders that dispense food into the tank at set intervals. They are a good choice for lowering the risk of a daisy chain, the potential fire hazard of wiring that uses an exorbitant amount of adapters in the same outlet simultaneously.

2. What is pH and how is it relative to my tank?

pH is the unit of measuring the acidity level of a substance. When a tank’s acidity is too high or low, it can cause debilitating effects on the fish and will lower their lifespan. Saltwater fish generally need an alkaline pH of 7.5 to 8.0 or above. Freshwater species are best kept between 5.0 to 7.5 pH.

3. What happens when the controller randomly shuts off?

If your aquarium controller has the ability to save your calibrations, it will simply revert to what was set before shutdown occurred. If not, you must re-calibrate the device since the settings will be reset by default.

4. What are the rods with suction cups for?

Controllers for your aquarium will have small probes that are placed into the water. Depending on the function, this will help determine anything from temperature to water levels. In pH controllers, the probes often have injectors that will allow pH calibration fluid to enter the tank automatically.

5. Should I get a multi-use controller if I already own individual devices with the same features?

If you have controllers but are missing one feature that is not available on the device you already possess, it is suggested that you simply acquire the item that you need and refrain from multi-use controllers. However, if you are looking for something to consolidate the tools used for your tank, they are advisable. As a consumer, it is ultimately your personal preference.

6. Do temperature controllers prevent the heat from getting too high?

Some will only notify you when the temperature reaches a point that is set by you prior to using. Others can cool down the tank by simply switching off the controller for an extended period.

7. Are aquarium monitors good for nano tanks?

Yes, nano aquariums can use controllers as well. Many of them are smaller than ordinary controllers but some products will have no problem fitting into small aquariums. If you own a nano aquarium, it is recommended that you look for controllers that will not take up too much space in your tank.

8. Why are some controllers not advertised for aquariums?

Being that temperature controllers can be used for a variety of purposes, some consumers will use them to monitor the temperature of tanks that hold snakes, lizards, and rodents. Other uses include refrigerators and deck ponds.

9. What is pH calibration fluid?

The fluid, alternatively known as pH buffer solution, stabilizes and eliminates lethal impurities in the water of your tank. Most pH controllers are sold with packets in which the solution is added to the probe.

10. Can I change the units of measurement in temperature controllers?

Most temperature controllers sold today allow measurement units to be read in either Fahrenheit or Centigrade. If you are not sure, read the device’s instruction manual online (if available) or find the location in which the product of interest is manufactured. Since the United States uses Imperial units of measurement, products sold in the country are often set to Fahrenheit by default but can be changed to Metric System units.

11. What trait do high-quality controllers have in common?

Aquarium controllers of high quality are built using parts that will not break easily, give accurate readings that rarely fluctuate, and possess indicators to alert you when the tank requires your attention.

12. How long do ph calibrators last before they need to be repurchased?

Most pH calibrators will last for about 12 months before a replacement is needed. However, some can last longer so long as they are cleaned of dirt and debris periodically. It is also advised that probes remain wet for the entirety of their use since they can malfunction when left to dry in the air.

13. Are some controllers specifically built for salt and freshwater tanks?

Most controllers can be used for both. No matter the salinity content of the aquarium, your tank’s temperature and pH can change. Spectrometers are no different since aquatic plants and reefs can be suited for either fresh or saltwater.

14. Why are alarms so important?

Having an alarm built into your controller allows you to be notified when changes occur in the aquarium that can pose a risk to the livelihood of the fish and vegetation living in your tank. Remember to always set your controller to the correct temperature requirements. The following are the best temperatures for your tank, based on species and salinity:

  • Reef aquariums – 75-78 degrees Fahrenheit (23-25 degrees Centigrade)
  • Marine Fish (Saltwater) – 78-82 degrees Fahrenheit (25-27 degrees Centigrade)
  • Freshwater Fish – 76-80 degrees Fahrenheit (25-27 degrees Centigrade)

15. It there an all-in-one product that can measure LED, ph, temperature, and water levels?

Few controllers are equipped to measure all of these readings in one package, although some brands do come close. pH controllers are often not found on multi-use devices.

16. Will the monitor affect the performance of my aquarium filter system?

Controllers do not inhibit the functionality of filters since they only rid the tank of waste and other debris. In fact, a good filtration system will allow pH controllers to function better since fewer impurities will be in the water.

17. Should I buy a surge protector with a controller?

As stated earlier, plugging in too many adapters to multiple surge protectors that are grounded into one socket can create a potential fire hazard. Only use an additional cord if you are sure that you are not overloading the plugs with too much voltage.

18. Are controllers compatible with my smartphone and computer?

Some aquarium controllers are compatible with smartphones. If the manufacturer builds the product with WiFi connectivity and operates a server, you can connect your phone to the address associated with your controller to get readings. Other brands have their own applications but do not always offer the same programs on every operating system.

19. Will the size of my aquarium affect the performance of the controller?

Aquarium monitors will normally show the recommended sizes for their products. Most controllers can be used in small nano aquariums to tanks able to hold close to 100 gallons of water.

20. Why are aquarium controllers important to my tank’s functionality?

While it is possible to keep your aquarium’s fish and reef specimens healthy without a monitor/controller, doing so becomes exceptionally easier when using such products. Your fish with live longer and less time with be spent on the upkeep of your tank since the most vital functions become automated.

1. Hydor Smart Level Controller, Automatic Top Off, ATO



Hydor’s Smart Level Controller is definitely an energy saver. Its voltage consumption will remain low, decreasing the number of funds in relation to your electricity bill. Which is great, since a dual alarm system can alert you throughout the day when incidents arise in the tank that may require your attention. It will light up and make sounds (not too loud) from the body of the device itself, which has a pillbox shape. To activate the sensors, two suction pieces are required. One of them goes in the outer portion of the tank while the other sticks halfway between the water and the surface. Both should be parallel so they can give accurate readings.

If you own more than one aquarium that has variances in size, consider Smart Level Controllers; they can accommodate any tank size and will prevent unwanted hazardous overflows of water leakage.


  • Magnets fitted on the sensors to hold them in place
  • Built-in visual and sound alarms
  • Easy setup


  • Slight sensitivity may cause false alarms on the sensors
  • No digital readings

2. Inkbird Itc-308 Digital Temperature Controller Outlet Thermostat, 2-stage



Inkbird produces several temperature controllers that can be used for a variety of purposes. The Itc-308 model is suitable for aquariums. At first glance, you will notice a digital monitor on the front of the device, which is for temperature readings. They can be observed in both Fahrenheit or Centigrade. The alarm can also be tweaked to your own specifications; just calibrate it to the number that you wish when you want the tank to alert you when it gets too hot or cold. It has about the same amount of decibels as a smoke detector, so you should know when your aquarium needs your attention.


Setup should be no problem. Just plug the machine in and turn it on. As for voltage, the highest output is specified at 110 volts maximum. With the dual relay output, you can monitor two pieces of equipment simultaneously if you choose to do so. If you are looking for a product to go along with other controllers that do not possess the ability to know when your tank is hot or cold, try the Itc-308.


  • The Display is bright, easy to read, and responds quickly
  • The alarm is loud enough to be heard outside the room of the aquarium
  • Dual settings allow users to increase or decrease the temperature


  • When the alarm sounds, the device turns off and must be reset
  • Short cables

3. SENEYE Reef Aquarium Monitor and Par Meter


If you have an aquarium with lots of corals, the Seneye Monitor is one of the best controllers for keeping them lively and bright. It will allow you to have improved awareness of the parameters that keep everything in your tank healthy. Alerts are automated at the slightest changes in your aquarium’s temperature, NH3 levels (ammonia), and pH.

Other components can keep track of the lighting (LUX and Kelvin), and PAR sensitivity. Seneye will also work with LED, although the PAR reader is not dedicated exclusively to such lights. A WiFi adapter will show readings on your PC or laptop. It doesn’t use an ethernet cable, which raises the possibility of connectivity issues if there are multiple tanks or electronics in the same vicinity that possess wireless signals. Furthermore, if you have a Mac, Seneye’s application cannot be used. Alternatively, you must visit a dedicated server to have your tank’s readings shown on the computer.

Overall, the Seneye is suggested when temperature controls are not enough. Once the installation is complete, you can have your readings shown to you in any place with internet accessibility. Just remember to keep other wireless devices away from the sensors, so that disconnections will be kept at a minimum.


  • Spectrometer readings of LED fixtures
  • Can gauge the ammonia content in the tank
  • Accurate readings of most occasions


  • Possible interference issues when used in areas with many wireless signals
  • The Seneye application does not work with Mac OS X, only Windows

4. Milwaukee pH Controller



The Milwaukee pH Controller, as the same suggests, is specifically designed to keep track of your tank’s acidity and alkaline levels. The readings can be set from 5.5 to 9.5 pH, which will flash an LED alarm when the numbers are too high or low. It is best suited for those with reefs or sensitive aquatic plants in their aquarium.

When viewing the probe (the part that goes into the water for readings), you will notice a flaky substance on the tip. This is normal. Additionally, most aquarium owners will use the Milwaukee with a solenoid injector to have full control when the pH should be lowered. If not, a buffer solution is sold with the product to help keep acidity levels stabilized. Keep this in mind before you consider purchasing the product.

As for temperature controls, they are not available on this controller, which means that you will probably need to get more extension cables to plug everything in, particularly if you already have such products at your disposal. Regardless, this controller should suffice in helping to increase the life of all aquatic species in your aquarium’s water.


  • Comes with buffer solution to help stabilize pH content
  • Cabled are long enough to be placed in spaces underneath a tank
  • Helps gauge CO2 additions easier


  • Does not monitor temperature or light readings
  • May occasionally fail to turn on solenoid for CO2

5. Bluelab CONTPH pH Controller with Hands Free Monitoring and Dosing of Solution



The Bluelab CONTPH Controller is another pH measuring product that is made to assist those who want to keep their tank fresh yet not end up with a device that is confusing to mount. Each monitor comes with a probe that does not require buffer refills. It should last about a year but can potentially go longer if care is taken to keep it free from residue buildup. pH levels will be scanned constantly, so long as the controller is turned on.

Settings are a breeze to change. A guide on the display screen with indicate all of the adjustment’s purposes. It is also compatible with a separately sold temperature control probe. When the acidity is too high, an alarm will sound and lock the device. Another great feature is how the CONTPH will automatically shut down dosing whenever overdosing occurs. The mount is water resistant and is built to hang on walls or cabinets.

While the LED panel does not come off when the monitor is on, there are few negative aspects of the product outside of the fact that other readings are not readily available (but compatible) with this Bluelab controller. It will work great if you own a large tank and need a reader that can be tweaked with more probes at a later time.


  • The pH probe does not require refills
  • Easy to use display and controls
  • Has a digital monitor
  • Compatible with a temperature probe


  • No other readings or control besides pH levels
  • LED does not go off automatically
  • Does not dose according to the tank’s pH

6. American Marine PINPOINT pH Monitor + Calibration Fluids



The PinPoint Monitor by American Marine is a small salinity monitoring product that will work for both fresh and saltwater marine aquariums. The readings display fast, showing up on the digital screen in seconds. Calibrations remain stable most of the time and do not require you to add anything when taken from the box for the first time.

Since the build of the device is quite small, it appears fragile and made from inexpensive materials. Care should be taken to not handle the controller to rough since it could become damaged. Another disadvantage is the calibration itself, which must be manually set by turning a dial. It is a little slow, requiring that you change the pH levels in tune with the amount of calibration fluid being used. There are no LED lights sold with the product.

Nevertheless, the PinPoint Monitor is a good device for your tank; the controls are rudimentary and do not demand lengthy setup to get everything working. You will not have to go back and change anything when you have your water’s pH content set at your desired measurements.


  • Straightforward design and controls
  • pH readings are displayed fast
  • Long cables make it easy to move on the fly


  • The design looks fragile
  • Calibration must be manually activated
  • No LED lights

7. RISEPRO Digital pH Thermometer Temperature Monitor With Replaceable BNC pH Probe



The RisePro pH Thermometer has a yellow design outfitted with probes that will scale both temperature and the salinity contents of your aquarium. The LCD display is large and has a built-in backlight to make reading in the dark easier. Installation is fairly quick and will work as advertised, with some notable improvements over previous Risepro products.

Calibrations during setup could prove difficult to hold at the level you want, with frequent reports of pH readings changing on occasion to levels that are inaccurate. For example, if your tank’s pH is calibrated to 6.5, the monitor could sometimes fluctuate to numbers that are higher or lower than the correct reading. As for the temperature gauge, these issues do not exist and will display accurately.

Because of the sporadic pH readings that could occur, this controller might be better suited for aquariums that have euryhaline specimens, or fish that can live in both fresh and saltwater/brackish conditions. If the temperature is a priority, then the RisePro will remain a good product for the entirety of your fish’s lifespan.


  • Lightweight design
  • Can read both pH and temperature levels
  • Digital display with bright backlight


  • May display inaccurate and fluctuating pH readings

8. Sequoia Aquarium/Reptile/Incubators/Gardening Digital temperature Thermostat


The Sequoia is a digital temperature thermostat that is used for multiple purposes, one of them being aquariums. It comes with a black gauge outfitted with a clear suction cup. It is waterproof so placing it at the top of your tank will not damage the device. Be sure to only place the probe into the water. When readings become higher than the threshold, the cooling mechanism will stop until space drops to the level that you calibrate for the device.

When you must turn it off, do not worry about having to reset all of your settings. The Sequoia’s computer will save all your predetermined calibrations and turn on with all of your data set to the same numbers as was previously implemented. The four buttons on the front are easy to navigate and work in the same manner as a digital watch. In fact, the red display font resembles an alarm clock at first glance.

While other attributes such as ph and spectrometer readings are not featured on the Sequoia, the accuracy and capability of changing your aquarium’s heat could be all that you need for your fish, especially if you do not have authentic corals and plants in the tank with them. It is suggested for any tank, no matter what salinity or fish are owned by you.


  • Suitable to use for a variety of purposes including aquariums
  • Buttons are easily navigable
  • Can change cool down the tank when the temperature warms


  • Only temperature controls and readings are available
  • While instructions are easy, the manual has errors in its wording

9. Finnex Temperature Controller/Titanium Tube



Great for all aquarium sizes, this Finnex controller comes packaged with a heating tube that will warm the water to the setting that you wish your tank to remain at while it is on. It can work for tanks as big as 80 gallons. The tube that comes with the bundle is 800 watts so you should be okay with a tank that has slightly higher water content.

If you live in an area that receives seasonal thunderstorms, you know that power outages are sometimes a common occurrence. When this happens, you won’t have to recalibrate the Finnex since the computer will save all of your settings when an abrupt loss of power transpires. The alarm built into the controller will go off when the temperature drops below the number that you set. Once it reaches the designated calefaction, the heater will turn off, along with the red light that accompanies the sound alarm.

While it would be better if the instruction manual were placed in a booklet instead of fixated on the box, there are few hiccups reported on the performance and accuracy of the Finnex. Use this item for all aquarium types if you need to fully automate the way your tank responds to sudden changes in its heat.


  • Powerful temperature controls
  • Can be used for large aquariums
  • Built with high quality materials that won’t break easily


  • The instructions manual is located on the box, making memorization of the controls difficult if thrown away

10. GROWNEER LCD Digital Thermostat Temperature Controller



The Growneer Digital Thermostat has a beautiful LCD display capable of reading all measurements that are relative to your tank’s ideal temperature. When that changes, there are tools available to help get the water back to the correct numbers that you require. With its dual relay output, you can make the temperature fluctuates higher, depending on the needs of your fish. The build is tough, made from ABS plastic and resistant to fire.

The probe is submersible, so you can place it into the water and still get accurate readings on the display. The alarm can be set to high or low, so if the flora and fauna in your tank become exposed to below average temperatures, you will be notified when that happens. There are no pH or LED reading components sold with this Growneer product.

When the device is plugged in, the controller will begin displaying relevant information on the screen. Units of measurement are shown in Fahrenheit or Centigrade. It is best for people with medium to large aquariums situated in rooms that are cold.


  • Ergonomic design that is easy to hold and operate
  • Bright LCD display
  • Has an alarm system to notify of temperature changes


  • No auxiliary measurements (cannot read salinity and LED levels)


The best aquarium controllers will allow your tank to shine as one of the centerpieces of your home. After reviewing the products and information found with the answers provided in the guide, you should be able to narrow down your search based on the type of fish and water content they require to be happy. Choose the right controller for your tank by retaining the information and comparing the options that interest you the most. By doing so, you will end up with the right tools for keeping your aquarium in shape.



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