Optical Sensory ATO frustration

[His Coral Highness]

I got this ATO system off Amazon and it seems like a common enough one with decent reviews (and a lot of the exact same just under different brand names). I have it hooked up from a reservoir to my sump and got the optic sensor to right where I needed it… and then it just fills arbitrarily, always way overshooting the mark. Is it something I am doing or are these just unreliable? Do they just project a laser straight out in front of them and a stray wire could be setting it off? Or do the just detect water right at the surface of the sensor? I’m trying to troubleshoot this thing but it’s just been a pain for me so far. Thanks for any help.

 

[jabberwock]

I have a similar one. Been reliable for 6 months. The only time I had trouble with it was when I changed up my back chamber filter sock configuration, and it overfilled alot. Got to keep the salt creep off of it. Do you have it refilling in your back chamber/sump or in the main tank? How many gallons?

 

[His Coral Highness]

I have it in the final baffle of my sump which has the return pump in it. I’m wondering if the problem is that the chamber is small and that has something to do with it? Or that the baffle it is facing is black and not clear. I have the sensor on the lateral most side of the sump, facing inwards.

 

[His Coral Highness]

The ATO reservoir is a 5.5 gallon Aqueon tank. The sump is a 29 gallon tank, but it’s really just measuring the water level of the final two baffles, so that volume is much smaller

 

[jabberwock]

I have the fill hose in the second baffle, sensor in the third baffle clipped on the back facing the tank.

 

[His Coral Highness]

I have the fill hose in the second baffle, sensor in the third baffle clipped on the back facing the tank.

I have a similar set up then, just with the fill hose and sensor both in the last compartment. I am wondering if the hose is getting picked up by the sensor? I tried to keep it as out-of-the-way as possible