IceCap Gravity ATO
SKU: IC-GATO
MSRP: $ 20.78
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Available Through Authorized Retailer
- 100% Electricity-Free Operation: Operates cleanly off gravity and atmospheric pressure changes, saving space and completely removing the risk of stray voltage or power outage failures.
- Universal 500ml Basin Bottle: Ships loaded with a dedicated, lightweight 500ml (500ml) plastic water bottle reservoir that screws directly upside down into the mounting base.
- Triple Thickness Rim Inserts: Packages three specialized spacing structural inserts to ensure a snug, wobble-free mounting grip across various common glass and acrylic rim sizes.
- Flexible Silicone Tube Control: Dual-line silicone tubing paths establish the pressure seal and water delivery lines, easily trimmed to customize your exact display water line.
- Preserves Micro-Tank Salinity: Provides constant, incremental drop-by-drop top-offs, completely preventing drastic salinity shifts that can shock sensitive nano reef inhabitants.
- Ultra-Compact Footprint Layout: Tiny overall physical footprint slips easily onto small rim boundaries without cluttering your desktop view or interfering with light fixtures.
IceCap
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IceCap Gravity ATO — Non-Electric Nano Auto Top Off (IC-GATO)
The IceCap Gravity ATO System (SKU: IC-GATO) is an authentic, completely mechanical water management device distributed by CoralVue to preserve environmental stability in compact nano aquariums, desktop freshwater displays, and miniature saltwater frag grids. Evaporation is an unforgiving enemy in small-format setups; because the overall water column volume is tiny, losing even a few ounces of fresh water causes a rapid surge in salt concentration, straining sensitive corals, decorative shrimp, and small reef fish. While automated electronic systems are great for larger show tanks, adding bulky magnetic optical eyes, wires, control modules, and secondary feed pumps to a micro desktop tank creates unnecessary visual clutter and physical hazards. The IceCap Gravity ATO resolves this by condensing your top-off requirements into a single, power-free mechanical bracket.
The system utilizes basic principles of physics and atmospheric pressure differentials to self-regulate. When screwed together and seated onto your tank rim, two custom-trimmed silicone tubes extend down into the water column—one cut slightly shorter than the other. Under standard operation, the water line covers both tube tips, creating a structural vacuum seal inside the inverted 500ml reservoir bottle that holds back the fresh top-off water. The moment evaporation lowers the aquarium's surface line to expose the tip of the shorter tube, air breaks the vacuum boundary and bubbles upward into the bottle. This pressure equalization immediately allows a corresponding amount of fresh RO/DI water to slip down through the longer tube, raising the water line until both openings are safely submerged again. Simple, efficient, and highly dependable, this system keeps your micro ecosystem perfectly balanced.
Key Features
Eliminates Electronic Failures: Free of moving mechanical components, magnetic sliders, or circuit boards that can fail from salt spray, mineral scale, or temporary house power grid failures.
Simplifies Maintenance Routines: Eliminates remote reservoirs, loose under-cabinet plumbing lines, and wire management paths—simply unscrew the bottle, refill it with fresh RO/DI, and thread it back in.
Tailored Elevation Setup: Slanted tube tips allow you to fine-tune the high-water threshold to accommodate the unique wave action or water level requirements of your specific display.
(Note: This self-contained nano top-off setup includes the primary Gravity ATO base hub, 3 rim-gap sizing inserts, a 500ml water bottle, and silicone tubing lines. Replacement bulk tubing is sold under separate product categories).
What’s Included:
(1) IceCap High-Impact Molded Gravity ATO Mounting Base Hub
(3) Interlocking Rim Gap Spacing Inserts (for variable rim profile adjustments)
(1) 500ml Lightweight Inverted Polymer Reservoir Bottle
(1) Length of Flexible, Reef-Safe Silicone Pressure Line Tubing
Technical Specs:
Official Manufacturing Title: IceCap Gravity ATO
SKU / Factory Part Identifier: IC-GATO
UPC / Factory Barcode Identifier: 6972809520826
Primary System Operating Layout: Mechanical Gravity & Atmospheric Pressure Differential
Power Requirements / Volt Matrix: 0 Watts / Fully Non-Electric
Total Included Reservoir Volume: 500 ml Capacity
Target Enclosure Application: Nano Aquariums, Mini Frag Displays, Bowls, and Desktop Tanks
Tank Rim Interface Compatibility: Fits standard thin-rim glass, rimless acrylic walls, and small molded plastic frames via standard inserts
Warranty
CoralVue, Inc. hereby guarantees this product to be free from defects in material and workmanship for a period of:
- 1 Year
Warranty is activated on the date of purchase.
This Standard Limited Warranty applies and is limited as follows:
- To the product only as long as it remains in the possession of the original purchaser.
- To the product that has not been subject to accident, misuse or abuse.
- To the product that has not been modified, altered, defaced, or had repairs made or attempted by other than CoralVue, Inc.
- That CoralVue be immediately notified in writing within ten (10) days of first knowledge of defect by owner or his agent.
- That CoralVue, Inc. shall be given first opportunity to make any repairs, replacements or corrections to the defective construction within a reasonable period of time.
- Under no circumstances shall CoralVue and/or the Manufacturer be liable by virtue of this warranty or otherwise for damage to any person or property whatsoever for any special, indirect, secondary or consequential damages of any nature however arising out of the use or inability to use because of the product defect.
- Unbox your Gravity ATO assembly. Test your tank's glass or acrylic rim thickness against the base groove, and slip in the matching rim-spacing insert that provides the flattest, most secure vertical seat.
- Cut your included silicone tubing into two distinct lengths using a clean razor blade. Cut the bottom tip of both lines at a sharp, matching 45-degree slant angle (45∘). One tube must be notably shorter than the other to serve as the atmospheric air-trigger line.
- Push both silicone tubing segments firmly onto the twin receiving barbs located on the underbelly of the Gravity ATO plastic base hub.
- Fill the included 500ml container bottle to the brim with pure, un-supplemented freshwater RO/DI top-off water.
- Thread the Gravity ATO base clockwise onto the mouth of the filled water bottle until it forms a tight, secure seal. Quickly invert the bottle so the tubes point down and drop the entire assembly directly over your tank rim.
- Slide the unit along the rim until the bottom slants of both submerged tubes align directly with your desired high-water baseline. Over subsequent days, check the bottle line to verify that water smoothly dispenses whenever the water drops past the shorter tube.
Pro Tips:
- Always Cut Your Silicone Tube Tips at a Sharp 45-Degree Angle. When trimming your air-trigger and water-feed lines, never slice the silicone tubing straight across horizontally. Flat-cut tubing ends are highly prone to surface tension locks, where a stubborn bubble of air or water becomes trapped inside the opening, preventing the system from equalizing pressure when the tank water drops. Slicing the tips at a sharp 45-degree angle shatters this surface tension grip, allowing air bubbles to break free and move upward smoothly.
- Do Not Add Liquid Buffers or Kalkwasser Solutions Into the Top-Off Bottle. Because this system relies entirely on tiny physical air pathways to regulate pressure, you should only fill the 500ml reservoir bottle with pure freshwater RO/DI. Never mix aquarium additives, mineral supplements, or calcium-saturated Kalkwasser powder directly into the bottle. As the fresh water slowly creeps out, evaporation can cause concentrated powder minerals to crust over and crystallize inside the narrow barbs, locking the pressure airways and causing the device to stall.
- Keep an Eye on Your Display Tank's General Water Line to Catch Salt Creep Blockages Early. While this non-electric layout completely eliminates pump burns and short-circuits, splashing water from nearby nano filter returns or air stones can slowly deposit salt creep along the exterior tips of the silicone tubes. During your weekly glass cleaning routine, take five seconds to gently pinch or wipe the submerged tube tips with a clean finger. This simple action clears away any micro-algae film or mineral crystallization before it can bottleneck the airflow pathways.