DDR – DŌS Dual Reservoir

This attractive fluid containment system stores your dosing fluids in style and tells you when it’s time to refill!
  • Each side stores two liters (2L) of fluid
  • Connects directly to your DŌS
  • Optical sensors inform your APEX when levels are low
  • Strong, cast-acrylic construction
  • Low-profile – won’t easily tip over
  • Easy to refill
  • Push-fit tubing connections
  • Use for 2-part (Alk/Cal), additives and other applications

Style Meets Function. Deceiving Capacity and No-Tip Design

The DDR has great style and will stand out in anyones equipment room. But it’s not just about style. It may not look like it, but each side of the reservoir holds an ample two liters (2000 mL) of fluid. For most saltwater aquariums that are dosing Calcium and Alkalinity to their aquariums, this amount is more than enough to last at least two weeks. If you were dosing other additives it might last months before needing a refill.

Speaking of refills, the DDR has easy lift off lids that make refilling it super easy.

The DDR was also designed to have a low center of gravity. This means, unlike other reservoirs on the market, it is very difficult to inadvertently tip over and ruin your day.

DDR Connector

Connects to Your DŌS

The DDR is the only dosing container on the market that connects electrically to your DŌS and uses optical sensors that alert you when your fluid has approximately 20% remaining.

This alert could be used to send you a text or an email, or even trigger other events on your Apex.  Also, when detecting water level, optical sensors are far less likely to fail than their float switch counterparts.

Apex Ready

Ready for Apex Fusion

Although not required, the DDR interfaces directly into your Apex Fusion dashboard. See in realtime your fluid levels and get an alarm when a reservoir runs low.

Optical Sensor Alerts

Optical Sensor Alerts

One simple connection links the DDR to the DŌS. No worries about fooling around with loose wires, float switches, etc. Just plug it in and it will show up in your Apex Fusion Dashboard.


Size (Approx.): 10.5″ x 8.5″ x 5.5″
Fluid Capacity (Approx.): 2000ml per side
Weight (Approx.):  2 pounds
Requires:  Apex, Apex Lite, or Apex Jr. and DŌS to operate sensors
Package includes: DDR, 4m of DŌS tubing

While the DŌS Dual Reservoir (DDR) is compatible with the majority of common additives that might be used in aquarium, some fluids can do harm.

Do NOT fill the DDR with:

  • solvents
  • fluids that contain solvents
  • methanol, or fluids containing methanol, e.g., RedSea NO3-PO4-X
  • ethyl alcohol, e.g., vodka
  • other fluids that may be reactive with acrylic or plastics

If you are in doubt as to compatibility of a fluid with acrylic or plastics, please contact the manufacturer of the fluid.

The DŌS may be used to dispense such fluids;  if you dose such additives, we recommend that they be kept in their original container, and that you place the DŌS intake tubing in that container for dispensing.

* Use only with fluids compatible with acrylic. Not to be used with solvents and other fluids that may be reactive with acrylic such as methanol.
If you are in doubt, please contact the manufacturer of the fluid to see if it will react to acrylic.