Hydrofarm Thermostat- Review of the Digital MTPRTC


hydrofarm digital thermostat mtprtc and cable

[dropcap]I[/dropcap] originally found this on Amazon, and it’s not bad.  If you’re already familiar with its features and what it does you can skip down to the middle of this write up for how it really does, and where it’s not so good at.

How the Hydrofarm Thermostat Works

There’s a “set” button you hold down to dial in the temperature you want. As soon as the number blinks, you can set the temperature anywhere between 68-108F using the “up” and “down” arrows.

The unit reheats when the temp lowers (2F below the temperature you set it to). An ON point can be set below the set point of 3F (say you set it at 77F, the heater is turned ON at 74F and turned OFF when the probe reaches 77F)


What Kind of Temperature Discrepancies can you Expect?

This unit seems to fluctuate +- 4 degrees. Swings of 5-6 degrees are not uncommon. That’s more expected when the probe is used in an open-air environment when it’s placed 6 inches to a foot away from the heating element.

The best possible accuracy you could get is setting the thermostat to 1 degree above the temp you’re after and it would teeter from 1 below to 1 above what you actually want. You’ll likely get that optimum range if you’re using a heating mat in soil, as described. Maybe that’s why Hydrofarm’s so hard-pressed to admit its use for reptiles. Can you blame them?

Keep in Mind…

This control of accuracy depends on the type of heating element you use, what sort of environment it’s in, and where you place the probe.

hydrofarm mtprtc plugThe temp drops by 2 or 3 degrees before it kicks back on so I would set it 1 degree higher than you need to keep it close.
MAKE SURE you hit “Set” again after you adjust to the desired temp.
For the serious reptile keeper, I suggest spending some more money and getting a proportional thermostat.

The Advantages of using a Hydrofarm Thermostat

The LED readout is very visible– able to be seen from several feet away. You don’t have to turn on a light to read what the temperature is at, since the light is always on. Other thermostats suffer without that feature.

Most “animal oriented” thermostats are steeper in price.
In comparison to other reptile probes, the probe of a MTPRTC is smaller.

For aquarium owners, Hydrofarm upgraded the probe to stainless steel for the option to be used in water.


  • For a thermostat that turns on and off, their accuracy is slightly less than a Vivarium Electronics (VE)…but those are about $100-$150 and still have a +- 1 degree gradient.
  • I often wish it would allow you to set a temperature lower than 68. The one thing that would be really nice is if it could control a cooling device also, but that’s probably stretching it.
  • It would be nice to be able to program it to alternate between temperatures (ie day and night temps).

-Only has one sensor/input, so can only regulate one heat mat at a time.
-Cord for the temperature probe is plenty long, it doesn’t need to be longer

One thing that would make these units better is if they had a setting or control for the differential between on and off.

The Price

The reason the price is so cheap is because unlike other thermostats, this one is an on/off rather than just controlling the amount of power that gets to the mat.


A valuable thermostat for the price- the functionality of this thermostat is good enough without paying the premium of some of the reptile-specific hobby devices and considerably cheaper than specialty ones for brewing.

There is nothing on the market in this price range that gives you a readout of the current temps with a nice bright red LED. It does the job without having to spend $50+ on brand name ones.

If Hydrofarm worked on their craft of marketing, they’d repackage this directed more towards reptile keepers and pet stores. Quite the opposite, they still label the MTPRC for heat mats. Grrr..

Ok, I’ll let it slide.

Do you own a Hydrofarm thermostat?  Does it follow through with your expectations of keeping temperature?  Share your experience with using the MTPRTC in the comments below!

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