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I am looking to change from useing a rheostat to a thermostat to controll my under tank heater. It heats a 20 gallon long tank. I am constantly messing with the rheostat. I am not looking to spend $150.00 - $200.00 on a thermostat. I have seen a couple that are a more reasonable price that I can afford for around $50.00 - $60.00 or so. Mainly the Zoo Med 500R and the Zilla 500W & 1000W Temperature Controllers.

My question is for the money wich of these do you recomend & why?. I can get either for about the same price.

Or are there any other inexpensive thermostats that you would suggest?

Also I noticed the zoo med one says it can be used for thier heat lamps or under tank heaters. The Zilla one says you can plug in any "incandesent heat sourse" so I am wondering does that mean heat lamps only and UTH would be bad for that brand?

You can use any and all for heat pads. In fact, lamps are harder on the thermostats because of the surge current that occurs with a cold bulb. Heat pads are a breeze.

You can do both dimmer and thermostat and get the fine-tuning benefit of the dimmer with the overtemp limit protection of the thermostat. Here is how:

1) First use a thermostat that has a relay output. You know it uses a relay if when the heater turns ON or OFF, you here a little "click" in the thermostat. I think all thermostats under $100 use relays because relays are less expensive. I have one of those A-Life jobs that looks exactly like Zilla 500, it is relay.

2) Use a dimmer that has a plug for the wall and an outlet for the heater. Plug the heater into the dimmer outlet.

3) Plug the dimmer into the thermostat output. Now the theromstat will turn the dimmer (and heater) off at the setpoint, and you can use the dimmer to dial in a more appropriate power level to the heater.
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Mark

What if the thermostat didnt have a relay? Would hooking it up like that be a hazard? Why do you want a relay type?

>>What if the thermostat didnt have a relay? Would hooking it up like that be a hazard? Why do you want a relay type?

The only contollers for herps on the market that for certain do not use relays are the $120-plus proportional units. They use solid-state semiconductor relays, which have no moving parts and can be switched many times per minute w/o wearing out. These are great for heat pads, heat panels, CHE's.

You want a mechanical relay type only if you want to put the dimmer in-line with it as suggested. If just using the thermostat alone, any type is fine. Proportionals are already kind of like a dimmer and thermostat in one. They heat to setpoint and keep it there with short bursts of voltage, whereas the mechanical ON/OFF thermostats bounce around the setpoint a bit because the heater is all the way on or all the way off.

The reason you want a relay type if hooking it up in series with a dimmer is that a dimmer already uses a solid-state semiconductor switch. If the thermostat does as well, as the proportional units do, they can conflict and you get no output. Not a fire hazard, just unexpected results.

I have yet to see a herp thermostat for $50-60 that wasn't the mechanical relay type. I do not have all models at my disposal to check for you, but there is little chance of that inexpensive of a thermostat having a semiconductor relay. And if by chance it does, just do not use a dimmer in-line with it and you are fine.

I already mentioned to listen for the "click" when the thermostat switches to tell if it has a mechanical relay. Semiconductors make no sound.
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Mark

Avoid ZooMed like the plague. Cheap crap made in China that is prone to failure and ZERO customer support.
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1.0.0 Cuban/Cayman Hybrid Iguana
0.1.0 Cuban Iguana
0.1.0 Corucia Zebrata
1.0.0 Ctenosaura Similis
1.2.0 Mali Uromastyx
1.3.0 Leopard Geckos
5.5.0 Uroplatus sikorae
0.0.2 Armadillo Lizards
0.1.0 Bearded Dragon
1.2.0 Angel Island Chuckwallas
0.1.0 Sulcata Tortoises
1.0.0 Western Painted Turtles
0.0.3 Red Eared Sliders

Does anyone know if either the Zilla or Zoo Med ones have relay output?

You really should spend at least $75 on a thermostat, get a nice Helix, Johnson or Ranco. There are other good brands too. I'll use cheapo Rheostats and dimmers, but never cheap thermostats. I've heard one too many horror stories of them malfunctioning and "frying" or "cooking" reptiles so I avoid them at all costs. To me, my $170 boa and all the food and time I've put into him isn't worth loosing to save some cash on a thermostat.
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Danne
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1.0 '07 BRB "Monroe"
1.0 '08 Pastel BP "Sebastian"
1.1 Leos "Bowser & Peach"
0.3 cats "Beast, Smokey & Thelma"
0.2 Dumbo (non-feeder) rats "Josie & Holly"
0.4.2 fish

Email = dshoback@eden.rutgers.edu