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The Barrel Tender is a unique device designed to automatically regulate reverse osmosis (RO) water production and greatly reduce the negative effects of TDS creep.  The Tender senses when the RO reservoir is nearly empty, then turns on the RO system until the reservoir is full.  This allows the RO unit to run for longer periods of time, which maximizes filter efficiency.  


This is the stand alone version and so does not require the need of an aquarium computer or controller. We use this and are very happy with it and that you do not have to use an additional controller or computer system.


The housing design incorporates a super bright edge-lit acrylic top, so you can see when it is active even when tucked away in the corner of your basement.  



Reverse Osmosis water reservoirs are conventionally difficult to keep full on a regular basis due to the need to manually turn the system on and then remembering to turn it off hours or even days later. 

Larger remote vessels can run dry due to "out of sight, out of mind" circumstances, resulting in having no water when you need it.  We have even heard of people using timers, keeping their RO reservoir in a bathtub to prevent floods caused from forgetting to turn the system off, and other wacky solutions that lead to frustrations with aquarium keeping. 


The Tender is a set it and forget it solution for top off water production.



TDS (Total Dissolved Solids) creep occurs when previously removed pollutants on one side of the RO membrane leach across into leftover water on the "clean" side.  When the RO unit is restarted, these pollutants are washed out with the first little bit of "good" water.  If you are using a Deionization (DI) postfilter, the DI resin then absorbs this little blast of pollutants, but the result is that the DI resin is exhausted faster.  Otherwise, the pollutants go into your aquarium.  You get this little pollutant blast every time the system switches on, even when using an autoflushing system. 


Running an RO unit for just a few ounces of water at a time, e.g., each time your top-off pump turns on and opens a float valve, means you are effectively losing the benefit of the RO membrane.  Conversely, If your RO system is allowed to run for longer periods of time, that initial pollutant blast is largely diluted by the large volume of clean water that follows.  If you are using a DI postfilter, this means the DI resin only has to pull out the initial pollutants once for a large volume of water, rather than many times over each small on/off cycle.  The bottom line is you'll save a lot of money on DI resin replacement.



Footprint: 6" x 4.5" 
Height: 5"

Power: 12v

Rated for booster pumps up to 135 PSI.

Requires an Auto Shut Off Valve (ASOV) on RODI unit. 


What's included:

Barrel Tender with your choice of control and plug type along with all the tubing, fittings and nuts and bolts to install on barrels up to 32" deep along with a drilling template.


See this template for dimensions required for installation.  We include a cardboard version of this in the box for installation convenience.

Barrel Tender V2 (EU/UK)

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