Reptile & Amphibian Forums

I emailed zoomed tech about two weeks ago inquiring
on the extremely high temperature of the hot rock I was
using -- which was 110 degrees and up! i took it out of the
tank, when i grabed it, the bleep ***** bleepin thing darn near
burned me. it's now trash, This is what they
replied with:

Subj: Zoo Med "tech advice"
Date: 5/29/2003 3:34:25 PM Central Daylight Time
From: colinp@zoomed.com (Colin Purcell)
To: SIX66GUNS@wmconnect.com ('SIX66GUNS@wmconnect.com')

Due to variables like ambient temperature, ventilation, insulation, etc. it is impossible to determine the actual temperature of any no-thermostatic heating element in a general sense. The surface temperature of the rock will be different depending upon those factors; however I can tell you that in an appropriate situation, under normal conditions, they usually run in the 95-100 degrees F range. If the air temperature increases, then the rock temperature will increase, and so on.

The only absolute numbers that I can provide you with are the wattages of the rocks:
RH-2 = 5 watts
RH-1 = 10 watts
RH-3 = 15 watts

Thanks for your interest in Zoo Med,

}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{}{
Colin F. Purcell
Zoo Med Laboratories Inc.
3100 McMillan Road
San Luis Obispo, CA 93401
(805) 542-9988 (888) 4-ZOOMED
colinp@zoomed.com
www.zoomed.com

That is an interesting reply you got there. The temperature that the rock produces is determined by how much current is passing through it. If you don't have a rheostat on the circuit, the rock will produce the maximum heat it can without burning itself out. What most people do is place all the heat at one end of the cage, this means you probably had a light over the rock. In this case, the temp under the light would be at or close to the operating range of the rock. In a room temp environment, the amount of heat generated by the rock would probably be the listed temp of the rock. Since most "rocks" are made out of clay, they will also absorb heat from the environment, if your rock had a thermostat in it, it would have sensed the higher temps and reduced the current flow through the rock, thus reducing it's temp to acceptable levels. For example, if your rock is not supposed to exceed 100F, and the temp under your light is 102, the thermostat would actually turn the rock off. Without a thermostat, the light heats the rock to 102F, while the rock also produces heat. The hotter the cage is where the rock is placed, the slower the heat flow ( or convection, I think) out of the rock. This allows the rock to retain more heat energy, and reach levels that can burn.

All in all hot rocks are not that great. Where they work well is if your reptile needs "belly heat" in order to help digest a meal. Most herps that need this spend a ton of time basking out in the open. You can provide this easily enough by placing a peice of slate, or similar rock under your light. The light will heat it and the herp can get heat from above and below. They do not help to raise cage temps, the herp has to touch the rock in order to get heat from it. If you are trying to raise ambient temps, a UTH will warm the end it is placed under, the substrate will diffuse heat well enough to keep the animal from burning. I use them in the winter to help keep my basking areas hot enough, as well as provide some heat at night. I unplug them during the summer though, as the hot end gets hotter than my snakes enjoy.

Hope this helps,
-----
Drew Z.
Member, NJHS

Yes, you are absolutely right!
But the temp on the surface of the rock
was 110 -I don't use any lights or lamps,
so maybe the rock was messed up or something
else -- I just had a negative experience with
that certain product, not with zoomed's stuff
as a whole.
I'm going to try a heat absorbing slate or
rock substance of some sort, and try the heating
it with a light, I haven't tried that yet.
Thanks for the advice,
Dallas

I've had ZooMed rocks that have become so hot, they've actually cracked!

Needless to say, I don't use them anymore. In fact, with few exceptions, I don't "add" heat anymore. There have been some interesting discussions on the old forums about heat and how it's generally over-applied.

If you have too, I suggest undertank heaters, like Cobra pads. They still get hot, but at least they're outside the enclosure and you can buffer them or add the thermostat.

Carl

Hey thanks carl and Bianca,
Dallas

I used to use zoo med heating pad but it ran insanely high)I should have used a temp controller)Either way the tank is 30 gallon long and houses a new mex milk so it had plenty of room to go on the cool side so nothing came of it.I switched the heating pad to cobra as some here suggested but zoo meds bulbs I do like and their light fixtures just not their heating elements.
Bianca

Was is it(or how many) are you keeping...? I assume since this is on the Kingsnake forum, that is what you keep.

I use heat tape to heat my rack, and that works great for me. Either that, or if it is just one snake, a heat pad available at any pet store is essentially the same thing. If you use one of these, you need to be able to control it. Go to Home Depot and for 15 bucks, you can by a dimmer(used for lamps) that you can just plug in to the wall(no wiring required). Then just use your thermometer on the surface of the cage and adjust to the temp desired using the dimmer.
-----
1SW
3.3 California Kings
1.0 Bearded Dragon
?.? Who knows...

Yes
1 king 50/50 female about 18 inches
and i'm going to get the dimmer tonight
thanks,

Dallas

Okay...hot rocks and made-for-reptiles tyep undertank heat pads are very, very, very bad. Why? there is no way to control the heat out put unless a therm. is directly resting on the surface. The best combo to use...is black or light glow lights above and if you want belly heat use a reg. human heat pad under the tank. When set on low the human heat pads do not get that hot to the touch...I have seen reptile heat pads that worked just like human heat pads but were water proof. Never use any heat source (unless a above light) that just has an on/off swich...and test the pad with your hand...if its too hot for your hand its WAY to hot for the snake...why?...because the snake's body temp is around 80 and ours is 98.6...so we are judging hot by a higher standard than the snake whos body temp (or standard) is lower. For ex..a 110 deg. heat source has a 11.4 deg jump for us but for a snake it is a 30 deg. jump from where it wants to be (80 deg). Look at it as if you ate a candy bar it would taste sweet, but it would taste less sweet if you just drank soda.