TCU Coolant Reservoir Empty – Do Not Use Water as a Substitute
Last updated: Oct 29, 2026
Problem
The DanioVision Temperature Control Unit (TCU) coolant reservoir runs out of coolant liquid mid-experiment, and users consider using water as a temporary substitute.
Details
The TCU requires a specific colored, anti-corrosive, anti-algae PC-type cooling liquid. Water is used in a separate water circuit and must not be placed in the coolant reservoir. Using water risks corrosion and system damage. Applies to all DanioVision TCU units.
Solution
1. **Do not add water** to the coolant reservoir under any circumstances, even temporarily.
2. Pause or stop any temperature-controlled operation immediately.
3. Obtain the correct Noldus-specified coolant liquid (colored, anti-corrosive, anti-algae PC-type cooling liquid).
4. Refill the coolant reservoir with the specified liquid up to the 'Max' level marker.
5. After refilling, set the TCU Operation switch to the 'Fill/Drain' position to purge any air, following the TCU setup guide steps.
6. Return the Operation switch to normal operating mode and resume the experiment.
7. If you do not have the correct coolant available, keep the TCU switched off until the proper liquid is received.