PTC Review

[Ken250]

I have a PTC 6 controlling the temperature for my tank, which is 120g with a 10g refugium. For lighting, I have two 250W MH bulbs and four 54W T5 tubes.












The ambient room temperature during winter time is around 23 degrees celcius during the day and 17 degrees celcius at night.

The temperature control is set at 25.5 degrees celcius (77.9 F) during the day and 24.5 degrees (76.1 F) at night.

The pump for for the PTC6 is an Eheim 1048 which is pumping the water through 6 meters of 1/2" tubing to the PTC6 which is in a room behind
the tank on a rack 1 meter above the ground. The Eheim 1048 pumping water to 1 meter in height will have a flow rate of 200 l/hr (the mid
point of the PTC specs.).

Prior to using the PTC for temperature control, I was using a Propeller Breeze 4 and two 250W Stealth heaters.





With the PTC 6, the temperature stays within 0.1 degrees of the temperature settings for the majority of the time during the day and night . The temperature is maintained at fairly constant levels and the large peaks and valleys of temperature swings have been eliminated. The tank spends more time at the desired temperature.

I have the hysteresis of the temperature control to 0.2 degrees and PTC will operate at max power when the temperature variation is 0.5 degrees.

If I wanted to decrease the temperature variation further, I could reduce the amount when the PTC operates at max power (to 0.2 degrees etc.). This feature enables you to choose how quickly you want the PTC to ramp up - cost benefit between your electricity bill and temperature control.

The PTC6 is currently using about 2.75kWh per day. I'm paying about $0.07 per kWh (marginal cost) so it costs about $0.19 per day to run or $6 per month during the winter.