ATO for 3.5 gallon pico?

[Evyllchyld]

I have a Pico Aquarium Barracuda AIO 3.5 tank that I've had laying around since I purchased it. I'm trying to make it as hands off as possible, to keep it stable since I want to keep SPS.

Does anyone have any suggestions on a good ATO system for a tank this small?

I would want it in the back, so you can't see it in the display.

 

[Reefing Madness]

 

[medusala]

Smart ATO Micro: https://www.amazon.com/Smart-ATO-Micro-Automatic-AutoAqua/dp/B0195D3LC6

I have it on my 25g. It's quite sensitive and uses an optical sensor to detect the water level.