Tunze Osmolator ATO 3155 keeps jamming

Idech · Oct 29, 2022

I’ve had my ATO since I started the tank, a year ago. For the first 10 months it was fine. I would scrub the optical sensor once in a while when I did maintenance and it worked flawlessyly.

Now it’s gotten to the point where it needs scrubbing every 7-10 days or it will just stop working. I don’t mind doing maintenance on it but how do people go away on vacation with an ATO that needs maintenance once a week ?

This is just not practical. Am I doing something wrong ?

Lowell Lemon · Oct 29, 2022

@rvitko
This person needs technical advise on Tunze osmolator.
Thanks in advance!

rvitko · Oct 31, 2022

Please never scrub the sensor, any scratches or scuffing will ruin the sensor, it should only be soaked in vinegar every few months for about an hour and then wiped with soft cloth. The sensor should be shiny, if it is dull and cleaning does not solve it, it may be scuffed and this may be the problem. If you dose any buffer or calcium, especially kalkwasser, in proximity of the sensor, this will blind the sensor rather quickly, kalk dosed near the sensor can haze it over in a matter of days.

Idech · Oct 31, 2022

rvitko said:
Please never scrub the sensor, any scratches or scuffing will ruin the sensor, it should only be soaked in vinegar every few months for about an hour and then wiped with soft cloth. The sensor should be shiny, if it is dull and cleaning does not solve it, it may be scuffed and this may be the problem. If you dose any buffer or calcium, especially kalkwasser, in proximity of the sensor, this will blind the sensor rather quickly, kalk dosed near the sensor can haze it over in a matter of days.

@rvitko thank you. I only « scrub » with my fingers, not even my nails so nothing to scratch it. The sensor is shiny like it was when I bought it.

I dose All for Reef, sometimes EVB calcium, EVB mag, sometimes Neonitro and Neophos. Also sodium silicate but rarely. Can any of those be a problem ? Just in case I’ll start dosing on the other side of the tank, farther away from the ATO.

rvitko · Oct 31, 2022

If you have no build up on the sensor, I don't think the dosing is an issue. It likely is an issue with the calibration or sensor. I only handle US service, I would contact Xenia North America. The only other possibility would be a refugium light, grow lights emit infrared and can blind the sensor.

Idech · Oct 31, 2022

rvitko said:
If you have no build up on the sensor, I don't think the dosing is an issue. It likely is an issue with the calibration or sensor. I only handle US service, I would contact Xenia North America. The only other possibility would be a refugium light, grow lights emit infrared and can blind the sensor.

I can’t see build-up, but right after I give it a finger scrub, it starts working again.

I don’t have a refugium; the ATO is directly in the tank. I will contact Xenia if the problem persists.

rvitko · Oct 31, 2022

Try the vinegar soak, the 2 part would be the most likely culprit, be very careful to avoid overdosing and dose slow and make sure the magnesium is above 1350 to avoid precipitation.

Idech · Dec 1, 2022

@rvitko I cleaned the sensor and it was working fine for a few days. Then I plugged it into a mechanical timer plugged into an outlet (to stop it from working during the night).

After maybe a week of being on the timer, it started not working properly again. It’s the first time I tried it on a timer. So I removed the timer and plugged the ATO directly on my power bar and it seems to be working again. It’s a little early to know for sure as it’s only been half a day.

But do you think the mechanical timer might have interfered with proper functioning of the ATO ?

rvitko · Dec 1, 2022

The most plausible is that while off salt and minerals cake up on the exposed sensor and blind it. Give it a thorough cleaning get the optic sensor off the magnet and soak it in vinegar for an hour to get it full descaled.

Idech · Dec 1, 2022

rvitko said:
The most plausible is that while off salt and minerals cake up on the exposed sensor and blind it. Give it a thorough cleaning get the optic sensor off the magnet and soak it in vinegar for an hour to get it full descaled.

Isn’t this build-up happening whether it’s on or off ? I want to make sure I understand.

I don’t think there is enough time in the 8 hours its off to expose the sensor. This is a 75 gallons tank. Or is there ?

Thanks