Topping off evaporated water manually means checking levels daily and never quite keeping salinity as stable as an automated system would - IceCap offers two very different approaches, one electronic and one requiring zero electricity at all.
Two Approaches to Auto Top-Off
- ATO EZ Automatic Top-off System - replaces evaporated water using three optical sensors instead of a mechanical float switch, avoiding the stuck-float failure mode that plagues float-based ATOs.
- Gravity ATO - tops off evaporated water using zero electricity, a simple pressure-differential design where water flows from an elevated reservoir as the tank's level drops.
Choosing Between Them
- Want optical reliability and don't mind running a pump and sensors? The ATO EZ avoids the mechanical failure points of a float switch.
- Want zero electronics and total simplicity? The Gravity ATO uses pure physics, no pump or sensor to fail.
- Concerned about a stuck float causing overflow or underfill? Both options avoid that specific failure mode, just through different mechanisms.
Setup Tips
- Always use a backup reservoir with a hard limit, regardless of which ATO you choose, as a safety net against any failure mode.
- Check and refill your top-off reservoir regularly so the system never runs dry mid-cycle.
- Position the Gravity ATO's reservoir at the correct elevation for its pressure-differential design to function properly.
IceCap ATO systems are available at Marine Concept Supply - order online or pick up at our shop in Wheeling, IL. Shop the ATO EZ or Gravity ATO, and browse more aquarium care products.
