Heaters · Adjustable submersible
EHEIM thermocontrol 50
Manufacturer-rated for aquariums of 6.6–15.8 US gal; adjustable 65–93°F.
50 W adjustable heater in a laboratory-glass jacket, with a control light and a shut-off if it runs dry. US shops still sell it as the EHEIM Jäger.
Consider: There is no display: you set it on a dial, check the water with a thermometer and recalibrate the dial if the two disagree.
US version, item 3612. Check what’s in the box before you buy.
Tank size EHEIM rates it for
6.6 to 15.8 US gal
Choose your tank to see where it falls.
Check it against your tank →Specifications that affect fit
- Manufacturer capacity
- 6.6–15.8 US gal
- Power
- 50 W
- Supply voltage
- 120 V / 60 Hz
- Dimensions
- 9.6 × 1.4 × 1.4 in (L × W × H)
To see what it costs to run, enter the watts on its label and your daily hours in the electricity cost calculator.
Before choosing this model
- Mount it upright, with the minimum water level mark under water and no deeper than 0.5 m (about 20 in), as EHEIM’s manual says.
- Put it where the filter’s flow passes it, so the warmth spreads through the tank.
- Don’t run it on a timer or a second controller: EHEIM’s manual says not to.
Our buying guides size it for these tanks:
A heater rated for your tank can still fall short in a cold room: see how to size one.
Check it against your tank → Something not working? See the troubleshooting guide.
Included items & upkeep
- heater
- double suction-cup holder
- 2 suction cups
Plan for the routine work
- Before you first plug it in, leave it in the tank water for 20 to 30 minutes, as EHEIM’s manual asks.
- Unplug it and leave it in the water for 30 minutes to cool before you take it out.
- If the dial and a separate thermometer still disagree after a day or two, unplug it, turn the red arrow to the thermometer’s reading, then set the temperature again on the blue ring.
- The cable can’t be replaced: if it is damaged, the heater has to be thrown away.
To budget for replacement media and supplies, use the first-year cost calculator. For how often and how to clean it, follow the maker’s manual.