heat light Q's

Guest · Post by **Guest** » Tue Jun 19, 2007 7:26 pm

Hi allI've decided to come back into Hermit crabbing after a 3 yr hiatus. There are so many things that have changed. Can't wait to get my crabbies again ^^I need help on getting a heat light for my tank. I was thinking of getting the exoterra nightglo light with the glow light to attach it in glow lightHas anyone used these two items before? Which size glow light is appropriate for the 15W or the 25W? And seeing the temperatures here in Melbourne is very low (it;s winter here) can i switch it on 24/7? or will that dry out the tank too much? Also do you just place the light fixutre over the tank, so the heat goes thru the glass lid into the tank? or do you put the light fixture inside the tank?thank you so much for any help

breezeetew · Post by **breezeetew** » Wed Jun 20, 2007 2:23 am

Putting the light directly on a glass lid can cause the lid to crack- be sure to leave venting room for the heat. If you notice, the info about the glo light says it can be placed directly on a mesh lid, it doesn't mention glass.Unfortunately, venting the heat out to save your fixture and bulb will make the lamp less efficient. The glass lid will get warm and radiate the heat inward to heat your tank.How large is your tank? The size of the tank is going to determine how many lights or what sized bulb you will need for heat.I have put the lighting inside my tank for better efficiency, but unless your tank is fairly large, you won't have room for an inside mount and the crabs will be able to climb the lighting. If you have a large tank, inside mounting is most efficient- less heat loss to the outside air, but smaller tanks can benefit from lighting as well.25 watts is not a lot of heat to go through glass. If you need much heat (more than one or two degrees) I would suggest a larger wattage bulb, but then again, I am assuming a large tank. I can make better recommendations from my experience when I know more what your setup is like. Hopefully JMT will notice this post and add more information- he is very knowledgeable about lighting and may have a formula for figuring out how much wattage you need to heat a certain sized tank.

PSUPrncess10 · Post by **PSUPrncess10** » Wed Jun 20, 2007 8:36 am

I have a 20L and actually use the 15W night glo bulb in just a desk lamp type fixture.... my lid is a custom plexiglass lid (I made it myself - ok with the help of dad, haha) so I can put the lamps almost right on the lid without problems (I have a regular bulb for daytime and night glo for nighttime heat).... The lights are on timers year round (I'm in northeast US), but I keep an eye on the temp and usually end up turning lights off in the summer when it's way hot (no central AC in the house).... so as far as how long/when to put the light on, just keep an eye on your thermometer in the tank (digital is best)and adjust accordingly....If you need to keep the light on 24/7 and find your tank is drying out, I use a very simple and easy to make homemade humidifier that keeps my tank at perfect humidity and keeps my crabbies active! Let me know if you want easy instructions/pictures!Welcome back to the crab addiction!

NewCrabber · Post by **NewCrabber** » Wed Jun 20, 2007 12:34 pm

Hey there bomjit! Welcome back. Has it really been three years?! What type of substrate did you use before? You might want to do some reading about the use of coconut fiber. Alone or mixed with playsand it's useful in helping to maintain humidity which can be somewhat of a challenge when using a heating source.

Guest · Post by **Guest** » Thu Jun 21, 2007 9:15 pm

thanx for the comments guys. I have a 10gal tank but it gets fairy cold here during winter, was only 3degrees celcius last night. And mum doens't turn on the central heating in the house during the night (she says it drys out the air) I do have a UTH but I've been reading and ppl have been saying not to use ONLY the UTH try a light instead. So that's why i've been looking into a light fixture. So if I decide on a light I should change my lid to a mesh lid and add plastic wrap?And NewCrabber, i used sand before but i do have coconut fibre (i used it once)so that should help with the humidity. And yes I can't believe it's been 3 years. (i think it was 3 years, maybe 2 and a bit?) I miss having crabs in the house.

Post by **JediMasterThrash** » Fri Jun 22, 2007 2:49 pm

Here's a copy of my post that includes my "watts per gallon" equation. Hopefully this will provide some useful information.Also, FYI, if your family is allowing the house to cool way down at night, and heat back up during the day, you can inform them that this actually uses MORE electricity (and more money) than keeping the the heat more consistent. You shouldn't lower the temp by more than 5o at night from the day temp. Because the energy it takes to warm the house back up 10o every morning is more than the energy it takes to maintain a consistent temp all night. It's kind of like how it takes more gas to accelerate from 0-60 than it takes to cruise at 60.I have numerous old posts lying around, somewhere. First, you need 24/7 heat. Your options are a moonlight simulating bulb (moonglo/niteglo,etc) or a ceramic heating element (not as recommended for beginners). This equation is rough, but it's just a starting point. Take your required nighttime temperature increase and multiply it by your tank size multiple of ten gallons, and this will give you a starting watts. This is for a fixture directly ontop of the lid. (JMT's constant: 1 watt/(oF*10g)) Set your target temperature at 80-85. Lets say your house is at 70, your night target 80, and your tank a 10g. Then the temp increase required is 10oF, and the tank is 1*10g, so multiply 10*1 = 10watts. So start out with a 15w. (If you have a 55g in the winter and your house is 65oF, target 80oF,then temp increase is 15oF, 5*10g, so 15*5 = 75watts). If you place a bulb inside the tat, with direct contact to the air, reduce by 50% (not recommended for beginners). If you place a bulb in a lamp fixture farther away from the tank, double it. Note that a clamp light designed for reptiles will be better because the metal shield reflects the heat and light towards the tank. A regular desk lamp will lose up to 1/2 the heat in the wrong direction. Once your 24/7 temp is up, now we want to simulate sunlight's UV rays. A dayglo/daytime bulb will do this, but it also adds heat. This is OK if you are creating a day/night cycle. If you want to keep your heat steady, use a flourescent (reptisun, reptiglo, etc), which outputs less heat. The number represents the amount of UVB, so a reptisun 2.0 is more than enough for a 10g, but a 100g might want a 5.0. Although most of the UVB is blocked by a glass lid anyway, but that's another topic. If you add day light, you'll need two fixtures, and place the daytime one on a light timer, which you can find for around 7$ at hardware stores or walmart. You can also get combo light fixtures, but I'm not sure if they have two cords. You might have to turn them off/on by hand. Place the tempometer just above crab height in a neutral spot along the back wall. The tank should not be placed in direct sunlight through a window, becuase it will heat up very fast. However, if the tank is big enough, a few rays creaping in won't hurt. If you have a day/night cycle, note that the relative humidity will fluctuate inversely with temperature. You need to have a source of water and a moist substrate to provide the evaporation needed to keep the humidity up. My numbers are conservative, and may not scale linearly. It's a starting point. Not intended to treat or cure. No warranty expressed or implied. Opinion of person. Oh, and a note about why the nighttime temp is less than 85. Most people keep the temp lower at night than during the day, so expect a 5oF increase of house temp during the day which will also boost tank temp by the same amount. Also gives some leeway for a day/night cycle.

Guest · Post by **Guest** » Fri Jun 22, 2007 7:44 pm

Wow thanx for the very detailed reply jedi master much appreciated. I think I've calculated the heat part correctly now.May I ask should I place the reptile lamp outside the tank and let it shine thru the glass lid, or should i have a wire mesh lid? And have the light sit on that.

Post by **JediMasterThrash** » Sat Jun 23, 2007 10:48 am

A glass lid has usually been the recommendation in the past, and it's the safest for new crabbers. However, if you want to take patience with advanced methods, a mesh lid might be better, because UVB will still be able to pass through to the crabs if you have a UV light. But you'll have to make sure that all of the lid that's not covered by the light is sealed with either a plexiglass cut-to-fit cover or a heavier-duty plastic covering.