ATO Reservoir

Simplicity Easy-fill ATO Reservoir

Elevate Your Top-off Routine.

Simplify your water top-off routine with the Easy-fill ATO Reservoir. It pairs with any ATO to maintain consistent water levels and salinity in your aquarium. The removable wide-mouth lid with splash guard converts to a funnel for stationary refills and fewer spills. This patent-pending design significantly increases the reservoir’s reach, making refilling in place a breeze.

Simplifies Maintenance

This first-of-its-kind ATO Reservoir features a wide-mouth lid that converts to a funnel for hassle-free refills. The unique lid design allows you to fill the reservoir in place, without removing it from your cabinet. The lid’s built-in splash guard helps reduce spills.

With the Simplicity Easy-fill ATO Reservoir, you can refill directly in your cabinet.

Place the front of the container near the cabinet’s front edge, leaving clearance for cabinet doors.

Remove the lid by gently lifting the front tab and pulling it away from the container at an angle.

Rotate the lid until it is upside-down with the back teeth pointing towards the back of the container.

Slide the back teeth below the top wall of the container to secure the lid in place, so that it extends past the front of the cabinet for easy refills.

Once you have refilled the container, simply return the front lid to the starting position.

Pairs with any ATO

The Easy-Fill ATO Reservoir offers universal compatibility with nearly every ATO on the market.  The distinctive removable lid provides large openings that can accommodate most ATO equipment, including the pump, tubing and power cord.

Reduce Algae Build-up

Opaque black sides help prevent light penetration to cut down on nuisance algae growth.

Space-saving Design

Compact footprint fits easily inside most cabinets.

Track Top-off Usage

Clear acrylic front panel has easy-to-read graduations to volume at-a-glance


5 Gallon ATO Reservoir
10 Gallon ATO Reservoir
5+ gallons (19 liters)
10+ gallons (38 liters)
Dimensions (Lid Closed):
6.0 in. (L) x 16.0 in. (W) x 15.25 in. (H)
8.0 in. (L) x 16.0 in. (W) x 22.0 in. (H)
Dimensions (Lid Open):
6.0 in. (L) x 20.5 in. (W) x 19.0 in. (H)
8.0 in. (L) x 20.5 in. (W) x 25.5 in. (H)
Pouring Lid Extension Length:
4.5 in. past the front of the container
4.5 in. past the front of the container
Pouring Lid Width:
4.75 in.
6.75 in.
Required Clearance:
20.0 in.
26.5 in.
Max. Return Tubing Diameter:
0.5 in.
0.5 in.
Max. Power Cord Diameter:
1.5 in. with cable groove
1.5 in. with cable groove
Black with clear front
Black with clear front
8.3 lbs.
12.4 lbs.
3-year Prorated Limited Warranty
3-year Prorated Limited Warranty