Lights as a warming source locked

Note, since this posting was done it has been discovered a hermit crab must have a night and day cycle to their lives to remain healthy.

i am really curious about the supplemental use of lighting especially, as i'm finding the temperature even with the UTH to be a little low... so i'd love to hear some responses here too...

I had to use supplemental lighting on my tank, because my house does not have central heating.
I have two combination light fixtures on my main tank, which is 120 gallons. One fixture has one day 90 watt incandescent bulb, one 75 watt moonglow, and a 15 watt ReptiSun? 2.0 UVA/UVB color correcting fluorescent. During the day, I turn off the moonglow, and at night, I turn off the two daylight lamps.
The other fixture is smaller, and only has two incandescent sockets, each of which currently hold a 75 watt moonglow. I run one or both of them at night, depending on how cold it is, and one during the day now in the winter.
I fully expect to have to change the bulbs out for cooler ones in the heat of high summer, if not turn them off during the day completely (except for the fluorescent), and I may even have to change out for a single 40 watt moonglow for summer nights.
I still have UTH, they are on thermostats set to 85 degrees, one at either end of my tank, about eight inches from the side.
The lamps will reduce humidity. I use two Tropic Aire misters on my tank, though currently, it is almost deep clean time, and the strawberries have drenched the sand to the point where I have one of them turned off currently. When the sand is dry, or just comfortably damp, sometimes I have the second one on, and sometimes not. They are rated up to a 55 gallon tank each. I had one at first, and it was not sufficient.
My day temperature is 80 degrees, the night temperature cools gradually to 74. The humidity creeps sometimes to 85% but I try to keep it at about 75 - 80%.
I was really worried at first when I began to use the lights, but my crabs act much more naturally now that their air temperature is stable. I have five species of crabs. I can't speak for the indo, because he is in ISO right now, but all four of the others (clypeatus (pp), compressus, perlatus (straws), ruggie) come and go in the light, the pps less than others. The straws and compressus bask directly under the day heat light, so I am of the opinion that it is actually good for them to be lighted in the correct conditions. They certainly seem to eat, molt and play much MUCH more actively than they did when it was just UTH, even in a smaller tank.
I'd be glad to answer any more questions you might have about my tank. The flu isn't completely gone and I can't tell if I missed anything!

Glad to see some exceptions being made to the UTH requirements for adoption. UTHs arent perfect by any means and in many instances there is a need for supplemental lighting. Back in the old days of a 10gallon tank, I used a moonglow bulb for heating purposes instead of a UTH and it worked perfectly for me. My experience is that once you get the humidity figured out, supplemental heating isnt a problem.Currently I use 2 smaller UTHs and also a flourescent light that while it doesnt give off a lot of heat, it does raise the temps a degree or two which is perfect for me.

Would there be a section to know how the crabber maintains the humidity level, along with monitoring the crabitat's 'substrate' temp? The substrate temp is just as important as the air temp. There have been times when using a UTH even that trying to get the air temp within range, the substrate temp is entirely too warm for the hermies. Using an over head light for warmth, would one of the criteria's be to provide a hut or such where the hermie can get out of the direct light if they want/need to?

Ah, Vanessa pointed out to me that I forgot to mention how much the UTHs on my tank cover the bottom.
I have two 11 x 17 inch UTH on the 4 foot by 2 foot bottom. They cover less than 40% of the total.

thank you so much for the very thorough response, kerie!
can you elaborate on the differences between the bulbs? i'm assuming the incandescent is your main "heat-providing" bulb? the moonglow bulbs what exactly makes them "moonglow"? do they provide heat or are they more of a soft lighting source for the nighttime? the UVA/UVB light what is its purpose?
also i am curious about how you chose wattages for your lights... was it kind of an educated guess thing, coupled with trial and error? i really have no idea what wattages to buy.
thirdly... my crabitat doesn't have a conventional aquarium hood/cover, and i'm wondering what kind of fixtures these bulbs fit into. do you know if it's possible to buy suitable lights for the crabitat that would fit in a regular desk lamp?
thank you so much for sharing with me! i've been meaning to get some supplemental heat/light in the form of bulbs, but i just don't know where to start!

There are three main types of heat bulbs for tank heating:

1) Incandescents, which are like regular light bulbs. There are day heat incandescent bulbs, and night heat incandescents — the moonglows. They are coated with dark rare earth, and simulate natural moonlight, and allow you to see what's going on in your tank at night. Some wattages, for whatever reason, are brighter than others.

2) Fluorescents. I don't use them for heat, but Bill does. I just use a single 15 watt color rendering bulb. The crabs are spectacular in simulated natural daylight.

3) Ceramic heat emitter bulbs. I have no experience with them; Bill uses one for at night though. They radiate heat, but cast no light.

When I first started out, I had been told over and over that lights were bad. And for a long time, they were. Long-term crabbers have very valid fears of lights, because they were told to use regular desk lamps of perhaps 60 watts with 10 gallon tanks. Coupled with the wood shavings they were told to use, it was deadly to hermits. So I can understand why lights were said to be a big no-no for so long.

But then Bill, on Hermies, started talking about his heating system (which varies considerably from mine, which uses higher wattages for heat), and so I decided to try it out. At the time I was using a 2 foot square by fourteen inch tall tank, so I put in a 15, then a 25 watt moonglow, and found that the crabs were happier, because their air temp. was warmer. Before, all they wanted to do was sit in their shells, even with the large UTH on the thermostat I had.

Then I got my bigger tank and knew I had to do something. Since my tank has a split top, with a solid permanent brace in the middle and two lids, on either end with screen tops, I chose to get 20 inch light fixtures. The glass brace in the middle of my tank is not rated for heat and will crack. I put one ESU or Fluker's combination hood (I have one of each) over each lid, which are 18 inches wide. This way, no heat gets onto my middle brace. I could have bought a 48" combination hood, but that would have put my glass at risk.

I have two used pieces of tempered glass (and it has to be tempered to withstand the heat) from a hydroponics shop. They're the right size to cover each lid, and part of the center brace to take any heat exchange. They're from gardening light hoods, and cost me around $25 each. My combination fixtures sit on top of those 1/4 inch pieces of tempered glass, on top of the sliding screen lids, on top of the tank. My crabs can't push the top up to get out this way, even if they could reach it. I only have a small gap for the air hoses going to the filters, and the TropicAire? feeder lines. I cover the small gaps at the rear where the lines come out with plastic garbage bags as needed to raise humidity, and remove them to lower it.

I didn't know where to start with the heat, so I asked Bill to make some recommendations. He said for my tank and house temperature (which is 68 degrees or lower in the winter) I should start by trying at least 140 watts of combined light during the day, and slightly less for night.

I tried it, and it was too low, so I got bigger bulbs for winter and kept changing them around until I'd reached the optimum temperature range, which is the one I listed in my first answer to your post. I kept all the smaller wattage bulbs in a box for summer.

In all honesty, the cheapie fish tank hood I have on my 10 gallon ISO is a piece of junk, and I would go with the nicest hood you can afford. I'm going to replace the one on Rasputin's ISO ASAP, because the nut that holds the fixture into the hood won't grip. You get what you pay for.

A crabber named Bill stated that he had been using lights to help keep his air temp in his crabitat at the proper level for a few years. He does warn about monitoring the substrate temp as well as the air temp, and a close eye on the humidity level.

Here is a post I made on another site that might be helpful to you:

I have been reading many posts here and on other sites regarding heating and lighting for hermit crabs. It has lead me to rethink heating for hermit crabs and expermient with different methods of heating and ultimately to change heating recommendations I make personally to new crabbers. First of all, some hermit crab books discourage lighting for hermit crabs for fear it will "dry them out". This should not happen if it is done properly. Lighting can be beneficial to hermit crabs, giving them a more natural day/night cycle. Also, if the proper lighting is selected, it can improve color rendering, which can be important in the selection of foods and in other natural behaviors as well. Phillips has a lighting line you can get at home depot. I got their daylight simulator fluorescents-- 48" and 40 watts each for about $6 each. They provide a natural daylight lighting for my hermit crabs during the day. They also assist in warming the tank.
As for heating, many depend on UTH's and stay away from radiant heat sources like incandescent bulbs or ceramic heat emitters for fear again that this will "dry" them out. There are many other tropical species of animals that require high humidity and people have been properly lighting and heating them for years using fluorescent lights, incandescent lights and/or ceramic heaters. This should be no different for hermit crabs. The ideal range for our little buddies is reported by most sources to bew about 75-84 deg F. Hermit Crabs, like reptiles and amphibians are "ectothermic", i.e. they do not produce their own body heat and thus rely on their environment for their body temperature. Proper body temperature is critically important for proper digestion and other natural biological functions in hermit crabs. Chronic exposure to temperatures below this range is less than ideal and probably detrimental to the crabs.
A word about UTH's: They give you a warm spot, but do little to heat the air in the tank. They can also get too hot under the substrate and possibly harm a hermit crab that burrows to molt, or more ironically, one that burrows to cool off! I am not saying it is a bad idea necessarily to have a UTH, but keep in mind you should have a rheostat or thermostat to modulate the temperature so that it doesn't get too much above 85 deg F at the bottom of the substrate.
Overhead radiant heat sources are far more efficient at heating the tank for the same or lower wattage it would take in UTH heating, and they are easier to control with thermostats and/or rheostats.
ESU has a nice combo light fixture available in 20", 24", 30", 36" and 48" with 1 fluorescent fixtures and 2, 3 or 4 incandescent fixtures (safety ceramic fixtures rated up to 150 watts each). It also has another VERY important feature that other combo lights do not have. It has 3 separate power cords so that you can independently control day light, day heat and night heat with separate timers and/or thermostats!

Here is a link to a description of all 5 sizes of this product:


If that long link is broken, here is a link to a 24" one that contains information one the other sizes as well:

As for the type of fluorescent lighting you get for your hermit crabs, UVB is somewhat of an unknown for consideration with hermit crabs. We are starting to learn more about their calcium requirments and other animals with captive calcium requirements have benefitted from UVB lighting to help them synthesize Vitamin D3 to allow for proper calcium absorption. So, is a UVB fluorescent absolutely necessary for hermit crabs? Probably not. Is it harmful I don't htink so they are exposed to UV in the wild, as some crabs are active during the day, maybe not as much as night activity, but active nonetheless. A nice reptile UVB bulb will give you excellent color rendering. So too will the phillips daylight simulator fluorscent for a lot less money.

I think we should move away from UTH's as the staple recommendation for heating of hermit crabs. Reason 1 is the potential danger for overheating if a crab burrows down over the UTH. Reason 2 is that they are relatively inefficient at warming a hermit crab tank, especially a larger one, and they are difficult to modulate properly with a thermostat or rheostat. I believe we need to shift over to systems that allow for overhead radient heating that is easier to control and more efficient at warming the ambient air in the tank. You will still havea warmer area under the heat source an a cooler area away from the heat source, you will just have more efficient and more even warming throughout the tank, which is probably better for hermit crabs.
I am still in the process of experimenting with applying a small acryllic approved UTH to a TropicAire? Humidifier unit to see if this raise the temperature of the tank. This would be ideal, as the unit could then provide both needed heat and humidity.
A brief word about humidity: I have not had any trouble maintaing humidity levels in my tank using different overhead heating methods ( I now currently have the 2 40 watt fluorescent bulbs for the day for lighting and heat, and a 40 watt ceramic mounted inside the tank out of the way for night time heat. I have a 75 gallon tank, which is 48x18x22. You need to select proper wattage for your tank based on the temperature in your home and the size of the tank you are warming. I'll be happy to help people out with recommendations. Another crabber also makes some basic wattage guideline recommendations here at this thread:

Just page down and look for post from Jdei Master Thrash and you will find where he makes his rec's. Keep in mind yours may differ based upon the heat in your house and size of your tank.

My humidity stays in the mid 70's. Coconut fiber and two large basins of water also assist with humidity levels. As long as humidity levles are monitored and proper adjustments made, people should not fear "drying" their hermit crabs out. Your hermit crabs will probably thank you for nice even warmth and maintenance of a proper temperature range provided by overhead radiant heat that is controlled by a reptile thermostat or rheostat.

First of all, with the TropicAire?, my humidity is around 80%.

As for your comment on hermit crabs drying out and suffocating from lack of humidity, etc. This is a blanket statement that does not cover all. Sure, If you usea a 100 watt bulb in a 10 gallon tank you're going to havea problem. But a 15 watt or even a 25 watt bulb in a 10 or 20 will work fine (I know, I have set up my daughter's friends with 10 gal's with radiant heat and all is well).
My crabs are very active during the day. They have also been noted to be active in the day in the wild when conditions allow. If it is 100 deg. F heck yeah they're going to hide! However, with temp and humidity in preferred range, they will be active during the day my tank and others with similar setups are living proof of this. I have also noted significant basking behavior displayed in the presence of overhead radiant heat.
Look, there are many crabbers that use UTH's and no lighting and find that the best they can muster is 70, 72 or whatever other suboptimal temperature you can think of. Heating is a problem that still needs to be appropriately addressed by a lot of crabbers. Improper temperature high or low is not good for the long term survival of hermit crabs. Too low and they will not diget properly, be active or eat properly. UTH's aren't fitting thet full bill for all crabbers, especiallythose with larger tanks. More needs to be done and I am offering solutions from my experience.

Please also see:

Question for iso light/etc warming users:

In the past, it was always said to keep a molter in a dark, quiet, low traffic area.
My question is, if one has a premolter/molter in iso, and uses a light or hea lamp to supplement the heat, how is the darkness provided?
Another question, if one does use a light as a heat source, and a hermie burrows to molt, does this not make the top of the substrate warmer? (I am thinking of a summer day when the sun is beating on a cement driveway, or even in the grass just how warm it can get) It is said that it is a hermies naturre to burrow to get away from the heat and to cool off. Has anybody noted their hermies stay under longer maybe since the top of the substrate obviously stays warm most of the time due to the lights? Would this have them come p lessoften for the water they need?
I have not used a light to supplement heat, never had too. (we do however se a wood burning stove and majority of the time our home is WARM. (80-80+ F in the great room) I am trying to understand what precautions are taken, if any and..well, just the whole supplemental light heating.
Please all, do give feed back if you do use the lights as a supplemental heating source and how you do it to make it safe. Thanks!

In answer to your earlier post, Marie, in which you asked if hermits stayed buried more with lights, the answer is no, quite the opposite.
I have a digital infra red temperature gauge that I use on top of my substrate. Under the hottest spot of the daylight sun lamp, the substrate temp is 79.5 degrees.
As I look at my tank right this minute, I have a total of three perlatus, 2 compressus, and 3 clypeatus wandering around, eating, checking out shells, and climbing. My crabs will stand under the day lamp, shuffle their pincers into the sand in a comfortable resting position, and bask for hours. They LOVE the light.
The only issues that I feel that could be a problem is if someone either does not do something to keep the humidity in range, or if they use too large a wattage for their tank. And if someone has the proper gauges, and adjusts accordingly, these are non-issues.
Compared to how my crabs acted in a dim crabitat with just UTH, I feel heat lighting is actually more natural, and superior in every way, than just UTH alone. I also feel that it is better for them to live in a natural day/night light cycle, as the tropics are not constantly dim. All creatures have a circadian rhythm that also regulates their body systems, and light/dark cycles are what programs this. If a creature must live in dim conditions all the time, it is certain to have some sort of negative effect in the long term, whether a reduction in appetite, molting trouble, early death, etc. Just my personal opinion.
I only have day lamps on one side of my tank, the other side has a constant moonglow. That way, if they DO feel too hot, the crabs can hide on the darker side.
Not that they do, usually they bask or bury in the light side.

Thanks Kerie, but as you may of been able to tell from above, I have been in touch with Bill. :smile: So I basically already had an answer to that part. (I am after a bit more too though) I did get his permission to move his posts to this thread since the lighting supplemental heating is being discussed. Since he has been using lighting as a heating source for a few years, I decided to write to him. He also has a great link above for further reading, along with once there, there is another link within it for even further reading. (even a couple others who have been using lighting for a period of time successfully) Wink There are precautions one should take, and close monitoring is needed. Which some do not have that benefit due to having to work, or having to go to school. Here is an e-mail I received from Bill, (minus some of his personal happenings)

Bill’s e-mail to Ladybug15057:
“> As far as temp far down in the substrate, I have not specifically measured the temperature in the sand very far down in non UTH areas, but I have measured the temp in the caves that are buried under the high end of my tank beneath the deep substrate. The temp inside these caves stays pretty consistently from low to mid 70's depending upon how far into the cave you go and what time of day
> you measure. I believe the substrate just above the caves, which is the deepest substrate, would measure very similar in temperature. adiant heat will do a decent job of warming even several inches of substrate, which is something you would see if you dug down outside on a warm sunny day. In the wild of course, beyond a certain depth, the soil will be cooler-- in tropical areas and even where we are, when you get to a certain depth, the temperature above outside matters less and less and at some point of depth, the earth is generally the same temperature regardless of topside temps. I think most crabbers probably maintain 6" or less of substrate. Radiant heat will warm this fairly well, with enough insulation that the bottom of the substrate will still be cooler than the top, especially on the end where you have the heating device. In the cool end of the tank, the substrate will still benefit from some radiant heating even with the heating device at the other end
> by virtue of the air being warmed. The substrate near the bottom of the cool end will of course be cooler. In my tank, rather than having a heating device at one end, I have a high end and a low end of substrate. This allows the crabs to get closer to or farther away from the two 40 watt fluorescent day lamps, producing a natural gradient. At night, I have a 40 watt ceramic heater in the center of the tank to keep ambient air temp around 75.
> I have been on vacation from my regular job the last couple weeks with the baby, and I have been able to much more closely observe my hermit crabs. I have several that are markedly diurnal and exhibit basking behaviors. In fact, we have had sunny days where the winter sun came in through a nearby window, and the coral tree I have routinely fills up with 6-8 hermit crabs basking it's crazy! In fact, my wife and I joke around and say I don't see any hermit crabs basking hermit crabs don't bask, they're nocturnal all while we are sitting there watching everybody out sunning themselves! I have to say
> out of all species, C. perlatus seems to be the most diurnal. I have 6 of them and almost without exception, they are all out and about during the day, especially when it gets brighter from the light coming in from outside. I really do believe that all species of crabs I have benefit from the day/night cycles provided.
> To get back to substrate depth, the depth at which it cools will depend on the size of tank, type of substrate, heating device used, etc. Suffice it to say that as long as someone has a cool end and provides a reasonable substrate depth throughout the tank, the crabs will be able to burrow and find a comfort zone. Even in a 10 gallon tank, it is easy to have 6-8" depth on one end. I would recommend that the overhead heating device go on the end of the tank where the substrate was lower, but still provide a branch or somethign to climb on so the crabs can bask if they so choose. I would just make sure that the temperature in the closest spot the crabs can reach near the device does not
> exceed 85 to maybe 90 at the outside maximum. The temperature at the nearest climbing point to the fluorescent bulbs in my tank is around 84-86 and there are routinely a number of crabs at any given time up climbing. Crabs are all individuals, and some prefer to be warmer and some cooler, but I believe having access to a broad range of temps from the low 70's to the low to mid 80's is essential for proper thermoregulation.
> I find a number of mine love to burrow and even have their own regular spot that they go in and out of on a daily basis, especially C. compressus. I have little holes all of the place, which winds up being helpful for aerating my substrate (to maintain the natural vivarium setup which, knock on wood, is going well since I established it late November (aside from them eating just about all of the Baby's Tears I had planted hoping it would take hold and grow into ground cover-- oh well!))
> I hope this info helps, sorry to be so long winded. Let me know if you have more questions. A lot of this is things I have picked up over the years and kind of just comes natural to me, so without someone like you questioning it, some people reading my posts may not get the full picture with all the details-- all the details are in my head from experience, so sometimes when I write things may get left out from time to time that could be helpful to others.
> BK “

Rest of Ladybug15057 post prior to Bill’s e-mail:
So far to me, substrate depth may also play a factor as to the watt size of a light used too, not just the tank size.

The following are questions and answers from Bill to an e-mail that was sent to him by me:

Ladybug15057 question:
I remember you mentioning that you use PVC pipes to make caves in your substrate. Do you feel that the pipe would effect the reading of the temp any? Example, temp within the pipe itself vs. what the substrate temp would be at that same depth?

Bill’s answer:
There probably is some effect since the caves are hollow. I use some PVC pipe and some are cut up pieces of a platic trash bin. However, with long term stable ambient temps, I would imagine the temps are probably similar within 1-2 deg.

Ladybug15057 question:
Do you feel there would be a minimum required depth of substrate to ensure that lower in the substrate would be cooler?

Bill’s answer:
This depends on tank size and heating element used, as well as ambient house temp versus tank temp. I think in general, hermit crabs should have access to varying depths of substrate so they can find their own comfort zone. Most people can manage 6" depth, even in a 10 gallon tank. I set up a 10 gal for someone and there is a depth of about 8" on one end with a cave under it.

Ladybug15057 question:
Would there be a minimum light wattage suggested for each size tank? (10 gal more than likely would not require the size light that a 100 gal would)
Would it matter if one were to use a florescent light as opposed to an incandescent light? (even if the same wattage?)

Bill’s answer:
This depends largely on ambient house temperature, tank cover and type of substrate. It will also depend on if the light is over the tank (and at what distance), or if the heat source is inside the tank like my 40 watt ceramic. I can tell you it is possible to mount a 15 watt moon glo inside a 10 gal at one end. Distance from light/heat source to highest climbing point and to substrate, along with wattage, tank size and house temp, will all factor into temperature produced. This is also the case with UTH's-- house temp and substrate depth, as well as type of tank cover used all facto in here. The disadvantage with UTH's is they are fixed in one position stuck to the glass, and unmoderated yield 100 deg F temps at the contact point (this temp is consistent across the different sizes and inferring data on wattage from mfr's, most likely across brands as well). The advantage with overhead heat is that it is very adjustable. You can vary wattage by changing bulbs, altering the distance the bulb is at above the tank and by the type of cover used on the tank (open, closed, half & half, etc). Rather than make specific recommendations on wattage for tank size, it is more prudent to stress the purchase of a thermometer and also to start low and work your way up with regard to wattage until you produce the desired temps you are looking for in ambient air, warm end & cool end and substrate surface and bottom temps.

Ladybug15057 question:
Would it matter if one were to use a florescent light as opposed to an incandescent light? (even if the same wattage?)

Bill’s answer:
An incandescent or infrared (ceramic) heat source will give off a more focused radiant heat that should be placed at one end, preferably the shallow end of the tank. In my set up, with the fluorescent tubes running the length of the tank, there is a even, more general distribution of radiant heat as opposed to the more focused heat area produced by a bulb or ceramic. In my case, to produce a gradient, I have simply varied the height of the substrate so there is a high and a low end in the tank where they can be closer or farther from the lights. As far as total warmth (i.e. ambient air temp), total wattage used is the main factor as opposed to what type of heat element. Also, whether or not the tank is completely covered or not will factor in. For instance, I removed the plastic sleeve holding the glass partitions of my top together so that there is about a 3" gap in the center. This allows for some ventilation as well as direct exposure of the air in the tank to the warmth of the fluorescent light tubes. If the tank were covered in that area, there would be less direct heating and more wattage may be necessary to produce the same results.

Ladybug15057 question:
What about using an actual heat lamp? Any certain sizes recommended?

Bill’s answer:
Again, this depends on tank size, house temp, etc. It is best to start low and work up, monitoring temps closely until you have the results you want. It is also important to reevaluate throughout the year as temps change outside and in the home. Large tanks like mine (75 gal) and Roberta's (125 gal) may require actual heat lamps. I use a 40 watt ceramic at night, mounted inside the tank. Roberta uses I believe a 60 and a 100 watt ceramic inside the tank, modulated by thermostats. Everyone's sitution is different. My home is kept at 70 all the time in the winter, so my wattage requirements are lower than a person with the same size tank in a home kept at say 65.

Ladybug15057 question:
Would you say a thermostat of some sort should be required if one were to use these lights for a heating source?

Bill’s answer:
I would highly recommend using a thermostat no matter what is used for heating. It is a good safeguard to insure that the crabs don't overheat. Theoretically, you could set a heating device on a thermostat and leave it all year round. When it is warm in the summer, the heat element would probably not be turned on at all by the thermostat (it is prudent however to monitor temps and heating all year round). In the absence of a thermostat, careful monitoring in the set up of the tank is recommended. One thing with most reptile thermostats and lights is that they will actually turn the light on and off to maintain temp, as opposed to adjusting wattage to the light. You can get a thermostat that does this, they are called proportional thermostats and go for $100+. Helix Controls is one major company that carries them. So if you are using an incandescent light to heat, it is best to use a red light or night (moon glo) light so as not to disturb day/night patterns for the crabs. For me, I have my lights on a timer. The fluorescents are on 14 hours a day. When they go off, I have the 40 watt ceramic kick in, which allows for some cooling at night (40 watts night versus 80 watts daytime). I would probably recommend smaller moon glo bulbs (15 -25 watt) for tanks in the 10-20 range to start (again, depending on house temp and total heating need). For larger tanks requiring 25-40 watts of heat or more, I would recommend using a ceramic heat emitter for heat and daylight simulating fluorescents for lighting (keeping in mind to figure in the wattage the fluorescent will give off). This way, the ceramic can be kept on a thermostat and will go on and off as needed for warmth without disturbing the day/night cycle provided by the fluorescent on a timer. You can also get day/night timers (I believe ESU has one) where you can have a day thermostat setting and a night setting to allow for day to night cooling for a more natural approach. I can provide the 1000 watt Alife 3 outlet (identical to the ESU unit, I believe manufactured by the same company for distribution under different brand names) for $19.95 each and better pricing in quantity.

Ladybug15057 question:
Along with the change in accepting lights as a supplemental heat source, Vanessa mentioned also considering a heat rock. Any experience with this? Any safety precautions that should be taken? and if so, what?

Bills answer:
I personally don't care for or recommend heat rocks, not even for reptiles. High heat requiring reptile like Uromastix lizards can be provided with an intense basking area that has a heat source directed at a rock or perch. Here, the rock will absorb heat from above and also radiate some heat. Quality control is an issue here across brands, and there is no real regulation of temperature output, which can vary greatly. By and large, they are unnatural and can be dangerous. If one were to use one, I would modulate it with a rheostat or thermostat and check temperature carefully. A ceramic heat element like those you can screw into a socket and mount above the tank are probably best. There are even adjustable stands for lights so you can vary the height of the element above the tank. If a crab were to burrow under a heat rock, bad results would likely occur (i.e. akin to a night out at Red Lobster).

I hope this info helps. No matter what people choose to warm their hermit crabs with, it is important to take a number of factors into account. We can't just simply tell people to buy a UTH sized for their tank and slap it on and forget it. I know that is certainly not what CSJ does, but by and large I am sure you will agree that this is generally what happens out there. People may read a care sheet once to find out what to buy and then forget it. Many people out there have unregulated UTH's. The same applies to overhead radiant heat, that is why I am hesitant to just say use X watt bulb for X size tank because people will just do that and forget it as opposed to actually doing some trial and error and learning first hand how to obtain and adjust proper temperatures in their set ups.


Ladybug15057 wrote at the end of the e-mail question posting:
I hope this helps others as well by me sharing Bill's e-mails with me. It is important to monitor very closely, especially when making a 'change'. So, along with the other info on the Adopter Form, maybe ask for a substrate depth? One of my concerns still is, as the lights stay on, how far down does the hermie need to go to actually get cooled off? Of course, if the lighting was only on one end....the other very well could provide the coolness the hermie may need. As for the heat rock, I must say I agree with Bill. If there is a concern about a hermie over heating because of digging down to the glass where the UTH is, then a heat rock within the crabitat that provides much more heat would more than likely be a higher danger to the hermie.

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WhizKidsMom, 17:28 CST, Tue 01 of Jan., 2013: Happy 2013
ladybug15057, 15:37 CDT, Tue 19 of June, 2012: How time flies! June 17th was our 12 year hermit crab anniversary! Yepper, same hermit crabs too!!
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