AWC Auto Water Changer (Plus ATO)

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Discontinued by Bulk Reef Supply
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Auto Water Change Plus Auto Top Off 


Change your reef tank's water automatically with AutoAqua's AWC system. AWC & ATO All-In-One. Water changes are one of the most time-consuming maintenance tasks with saltwater aquariums. There has been plenty of debate over how much water you should change and whether it should be weekly or bi-weekly, but no one argues against daily water changes. Changing 2% of your water every day will greatly increase your tanks stability and potential for longevity. 

  • Includes pumps & tubing
  • Optical sensors = no moving parts
  • Secure tube holders
  • Siphon breaks


The simple system uses dual optical sensors, one for a high water level and another for a low water level. The high water level sensor acts as the ATO sensor, knowing when to refill your saltwater tank, from the freshwater reservoir. The top sensor also lets the AWC Touch controller know when to stop refilling the tank after a water change has occurred. The low water sensor acts as the minimum water level when a water change is in progress. During the water change, the output pump will pump water out of your tank our sump into a wastewater reservoir, or floor drain until the low water sensor is activated, telling the controller to turn on the input pump until the high water sensor is tripped, completing the water change and then reverting to a top off controller.

It is important to make sure the optical sensors are placed in the same chamber (usually the return chamber) where the water level will fluctuate during a water change. 



DC Pump Max Head - 6.5 feet

Flow Rate - 74GPH

Optical Sensor In-Tank Thickness - 0.53"

Optical Sensor Diameter - 0.78"

Magnet Thickness - 0.25" 

Max Tank Thickness - 0.5"

Controller Dimensions - 3.75" H x 0.6" W x 2.25" L

Sensor Cable Length - 10 feet

Pump Cable Length - 6 feet


What's Included?

1x Smart AWC Touch Controller

3x DC Pumps

3x Siphon Breaks

6M Water Tubing

3x Tube Holders

1x Power Supply

More Information
UPC 4714041211771
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Product Questions

Do you sell more powerful pumps that can connect to it? My refill pump is about 6 ft away from the DT and I am afraid it will fry soon as it looks like these pumps are pretty weak.
Thank you!!
Question by: Etienne Lemarie on Apr 18, 2020, 4:04 PM
Hello Etienne,

We have the Smart AC Socket which will allow you to use any pump you like with the AutoAqua brand Smart ATO, ATO Micro, or AWC.

This should be exactly what you need!
Happy Reefing
Answer by: Nick on Apr 23, 2020, 10:43 AM
What size tubing does it use? And could you respond with the link to said tubing?

Question by: Aaron on Apr 12, 2020, 8:14 PM
Hi Aaron,

The tubing for the AWC is 9mm Outer Diameter and 7mm inner diameter.
Answer by: Nick on Apr 23, 2020, 12:23 PM
What is the voltage for the this? Is it 240v?
Question by: peter on Apr 1, 2020, 10:13 PM
Hi there,

All of the products we carry are going to be 110v since we are in the US.

Take care
Answer by: Thomas Billington on Apr 2, 2020, 3:45 PM
can this unit pump the fresh water in before pumping water out? otherwise the return pump chamber in my sump would run dry.
Question by: Scott Evans on Aug 5, 2019, 5:23 PM
Hey there!

It will only take water in/out simultaneously. Doing them at the same time assures that the water level will stay the same.
Answer by: Thomas Billington on Aug 6, 2019, 12:39 PM
do i need to drill holes in my tank/sump to install the optical sensors?
Question by: andre millan on Apr 1, 2019, 9:36 AM
No drilling is necessary and we would recommend watching the manufacture video for help on the installation.

Answer by: Mark Schlough on Apr 5, 2019, 9:44 AM
Does this intergrate with the Neptune controller?
Question by: William Smith on Jan 29, 2018, 2:53 PM
The AWC is not compatible with the Apex Controllers. You could plug it into an outlet for an override, but there is no connectivity or added functionality to the AWC if it is paired with an Apex.
Answer by: Charlie on Jan 29, 2018, 4:44 PM
Do I have full controll of how much and when a water change takes place with this unit or are there limitations to what can be set?
Question by: Adam on Jan 29, 2018, 2:47 PM
You can program when the water change takes place through the controller, and how much water is being transferred will be controlled by the float valves.
Answer by: Charlie on Jan 29, 2018, 4:48 PM
Does this unit perform any type of substrate cleaning (ie gravel vac), or does it only change out surface water?
Question by: Rebecca on Jan 29, 2018, 1:08 PM
The AutoAqua AWC uses a pump to remove the water from the tank, and would not be able to remove or clean any sand or gravel. Doing so would make the pump fail pretty quickly.
Answer by: Charlie on Jan 29, 2018, 5:05 PM
Do the optics sensors require light to sense the water level? My fish room is in my basement which is always dark except for the aquarium lights and when I go down there. Probably even darker inside the stand. Do I need to add a small light over the unit?
Question by: Jake on Jan 27, 2018, 3:17 PM
The optical sensors will work without any light. It actually creates it own super low powered light source.
Answer by: Charlie on Jan 30, 2018, 5:09 AM
Can you program this system to do daily water changes of xx amount at X time or do you have to manually start the water change with the push of a button
Question by: Esteban on Dec 19, 2017, 10:49 PM
Thank you for reaching out to BRS!

The AutoAqua AWC can do both scheduled water changes as well as an on demand water change at the push of a button.

Have a great day.
Answer by: Josh Cuta on Dec 21, 2017, 4:09 PM