Equipment manufacturer WaveReef has released three ATO devices all armed with a triple-level sensor. The Nato 3M and SMT-03M are both variations on a common theme, comprising a water level sensor that sits in the pump chamber of your sump, and a tiny powerhead that sits within your ATO reservoir and pumps freshwater to replace evaporation. The magnet mount sensor has been redesigned however with a flat face and now boasts not one but three level sensors for triple protection against over-filling, according to its maker. It only takes one sensor to activate the top-up pump but WaveReef has added a belt and braces to ensure the pump doesn’t accidentally stay on and mess with your tank’s delicate salinity.
Invest in the SMR-400M however and you can use neat RO product water straight from the unit to then top up your ATO reservoir and in theory, you shouldn’t ever have to manually top off your auto top off. We have all left an RO feed running by accident and caused a flood, and when you work with commercial RO units in fish stores you can leave an RO unit topping up overnight and create a small river flowing through the shop by morning. WaveReef uses that same triple-level sensor, this time to be placed in the ATO reservoir itself to then open or close a solenoid valve and release fresh RO water into the vessel. Still not fully trusting a triple-level sensor with an RO feed? WaveReef includes a float valve to sit even higher than the level sensor to float up and shut off the RO feed if the three level sensors beneath fail to stop it. For those who dare to run a pressurized RO top-off feed straight into their sump’s pump chamber, the SMR-400M should cater to them too.