I've been running the Autoaqua AWC system on a 10 gallon IM SPS tank since December to perform 4% daily water changes. Once a week I fill up the 5 gallon reserve salt tank and empty the waste tank. At these water volumes/frequencies, I calculate that I replace ~70% of my total tank volume every month. The system has significantly reduced the workload for my nano tank and my corals look amazing.
I'd say the biggest advantage, other than reduced workload, is that it has allowed me to significantly increase feedings. Over the 4 month period I was unable to detect nitrates above 1ppm (NYOS kit). Recently, I begun experimenting with dosing potassium nitrate (increasing nitrate levels to 5ppm). Then increasing 2.5 ppm 1x per week. My phosphate levels bounce around a bit due to the heavy feedings but typically always below 0.03 ppm. Because this was a recent change it's unclear to me if there is any clear benefit.
The main flaw that I can see with this unit relates to power outages. If there is a power outage the system starts with the ATO off in the default mode. If I am traveling and the power goes out the only way to turn the ATO back on is to interact with the unit's touch screen. If there is a way to set the ATO to default in the "On" setting I would appreciate knowing about it (anyone know?).
I have purchased another Autoaqua AWC system for an IM-20 gallon to perform 2% daily changes. So, despite the glaring disadvantage, I still think it is an amazingly simple solution. It would be amazing if the unit could fully interact with my Neptune Apex.
