JBJ A.T.O. Water Level Controller

In stock
Out of stock
$92.00 $92.00

Discontinued by Bulk Reef Supply
- +


Why does BRS recommend this?

One of the most popular ATO systems available. The JBJ A.T.O system is by far the most cost-effective way of utilizing a safe and consistent auto top off system.  With multiple configurations, the JBJ A.T.O will fit almost anyone’s needs.  With linkable brackets adjust and secure float switches, you will need to add your pump of choice, the JBJ ATO system is a great top off unit for reefers on a budget.

  • Audible Alert
  • Adjustable timer based Safety
  • Multiple configurations
  • Visual LED signals
  • Includes float switches and brackets


Float Sensors

The A.T.O. is equipped with (2) float sensors that activate within seconds when your water level drops and automatically refills your sump or tank until it reaches your desired set point. Each float sensor has been designed with an exterior guard preventing snails & hermit crabs from attaching to the sensors.


Electronic Controller Module

Our state-of-the-art electronic controller allows for (2) modes of operation with a total of (3) different set up scenarios, allowing you more choices for installation for your unique set up. Our compact controller also incorporates a visible L.E.D. panel and an Audible Signal alerts when in operation mode.


Linkable Brackets

The kit includes commercial grade "Linkable Brackets" that can easily be adjusted to meet your height requirements, and securely positions your float sensors. No suction cups to lead to disastrous water spillage.


Pump Safety Protection

The A.T.O. automatically stops power to your return pump in your reservoir, in the event that your reservoir is low on water. This safety feature prevents pumps from running dry and failing. (Mode A- Example 1)


Note: No pump included.  The pump will need to be able to refill the amount of evaporated water in just a couple of minutes.  BRS suggest purchasing a pump that is just slightly larger and placing a ball valve to control the overall amount of flow.  We suggest looking into the Sicce Syncra Silent line of pumps or the BRS 50 mL top off pump.

More Information
UPC 8809168370015
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Product Questions

Is a person able to extend the cable for the float switches? It’s just not quite long enough to reach where I want my reservoir.
Question by: Nick Pallotta on Mar 20, 2022, 11:12 AM
Hey Nick, thanks for the question! This would likely require you to splice them, which we would not recommend doing unless the manufacturer indicates it as okay. Here is their info!
JBJ – (877)-374-9981 support@jbjaquarium.com
Answer by: James Johnson (BRS Staff) on Mar 23, 2022, 5:17 PM
I have a ATO Auto topper and when it shuts off my pump keeps siphoning water into the sump. Any help would be appreciated
Question by: Joe Hunsbarger on Feb 12, 2019, 5:25 AM
Hey there, Joe.

It sounds like the ATO discharge hose is positioned lower than the water level in your ATO reservoir which creates a siphon after the pump has been powered off. To fix this, you just need to raise the end of the ATO tube higher. For some reefers, it's easier to mount it on the very top of the sump or even up to the top of the display. :)
Answer by: Randy on Feb 21, 2019, 12:12 PM
I have a pressure RO feed directly to my tank and my old float valve ATO is worn out. Can this unit be paired up with a solenoid RO controller? If so, which would you recommend?
Question by: Mike on Jun 4, 2016, 10:33 AM
Great question!
This will have a single outlet which a pump or possible water solenoid could be attached to. We do not currently have an option for water solenoid however if you find one option with an outlet control this controller can turn it on and off. Feel free to let us know if you have any further questions!
Answer by: Connor on Jun 9, 2016, 12:35 PM
What is the factory preset internal timer set for? Thanks!
Question by: Timothy Gladders on Mar 23, 2016, 7:22 AM
Great question!
The max on time for the unit will be 14 minutes. Feel free to let us know if you have any further questions!
Answer by: Connor on Mar 23, 2016, 10:48 AM
My unit pumps as soon as power is applied. Like after a power outage. Is there a way to stop this. It pumps for a good 5 seconds until it seems to find itself and the sensors.

Question by: Wade on Mar 1, 2016, 7:59 PM
Great question!
We are not aware of this feature being able to be turned off. You may want to contact the manufacturer to see if there is any adjustments. Feel free to let us know if you have any further questions!
Answer by: Connor on Mar 2, 2016, 5:23 PM
Are we able to order the system with different voltage 240v - 50 Hz?
Question by: HELMUT DRESSELHAUS on Jan 26, 2016, 9:13 PM
Great question!
We do not have voltages other than standard North American. Unfortunately our products are intended for use in the US and Canada only. Feel free to let us know if you have any further questions.
Answer by: Connor on Feb 3, 2016, 5:07 PM
What kind of pump is recommended for this system thanks
Question by: Dan on Aug 29, 2014, 3:28 PM
Hi Dan,

Any low flow pump will work with this ATO. I ave personally used our 50ml/min dosing pump but find that it had trouble keeping up with large systems. I moved to the Auqa Gadget HydroFill ATO Pump due to the fact that it can be run dry without any problems, its self priming and it won't back siphon.

Another great option would be a small submersible pump like the eheim 300 or sicce micra and micraplus

Keep in mind these pumps are rated for low head heights so if you are running the ATO hose from the ground to the top of your tank you will need to go a little bigger.

I hope this helps!
Have a great day :)
Answer by: Bulk Reef Supply on Aug 29, 2014, 3:28 PM
Why do i still get drips of water out of my discharge hose non stop even after the vaccum pump has shut off the.
The vacuum pump is on the bracket at the top of the tank at lease 3 ft. higher then my R/O holding tank(no pump in here for the A.T.O.
Question by: jerry on Jan 17, 2014, 1:24 AM
Hi Jerry,
Is the water in your storage container higher off the floor then the water in your sump? If so that would create a siphon when the pump turns on and water would continue to pass to the tank after it turns off (regardless of where pump itself is located).
Answer by: Bulk Reef Supply on Jan 17, 2014, 1:24 AM
what's the recommended pump for the ATO JBJ? thanks!
Question by: werner on Oct 29, 2013, 6:21 AM
Hey Werner,
Really just about anything will work in terms of the ATO itself, its more about how far and fast you need to pump water. The most common pump is the aqualifter pump which pumps slowly and only goes a couple of feet. Otherwise if you need to pump larger distances you could use something like the 50ml top off doser.


Answer by: Bulk Reef Supply on Oct 29, 2013, 6:21 AM