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heating pads

tsheets
14 years ago

Hi all,

I was thinking of using a heating pad this year when starting seeds / through the young plant stage.

My space is in the basement, and a bit cool (upper 60's / low 70's). Everything went well last year, but, germination took a long while and growth was very very slow.

In looking at seed sources, the specific heat mats were pretty pricy (TGS for example has them for $65 - $100).

What sources / solutions do you all know of that is more reasonably priced?

Comments (43)

  • User
    14 years ago

    $65 - $100 seems a bit pricey. What size mat (how many trays)?

    I've recently searched for heat mat thermostats because my original one fried. I was surprised to see the HydroFarm mats on sale for as low as $20 - $25 for a 10"x20" mat.

    I was going to order the thermostat and an extra mat from one of the places listed until I saw the shipping costs to Canada, absolutely ridiculous (shipping was well over the cost of the items without duty). I ended up finding a reasonable source up north here.

    The mats can get quite warm. You may want to check your soil temp regularly or invest in a thermostat as well. I also find sitting the tray in a DIY styrofoam box helps even out the temp throughout the tray.

    I've never dealt with either one but since you're in the US you may want to give them a shot.

    Bill

    Hydroasis

    The Hydro Source

  • rockguy
    14 years ago

    I am using a heat pad like you put on a sore shoulder, maybe it's 12 X 16 inches. It has 3 heat levels, I use low. I set a metal sheet pan on it to put the pots on and after those peppers are sprouted, I move them to an area under light and start some more. The pad cost me a dollar at a yard sale 5-6 years ago.

  • tsheets
    Original Author
    14 years ago

    The ones at tomato growers were 15"x21" for the $65, 17"x38" for the $100. The description doesn't say anything about a thermostat, just that it will keep things 15-20 degrees warmer. :-(

    Thanks for those links! How important is the thermostat?

    The main concern I have with a standard heating pad as rockguy mentions is it isn't waterproof (I don't think anyway) and those get pretty warm. Most these days also shut off after a set time for safety reasons.

  • User
    14 years ago

    Hi again,

    Yep, I hear you regarding the solution rockguy is using. The cheapskate in me would love to use the setup he suggested but the realist in me knows I'm a klutz and I'd probably electrocute myself watering the heat pad ;-))

    Regarding the sizes of the waterproof mats I provided links to fit your "standard" 72 cell flats. It's entirely up to you but I prefer to stick with the single flat size. The mats will eventually fail and it's cheaper to replace one dead single flat mat than a 2 or 4 flat mat.

    As for the thermostat, I've added a link to it on one of the sites referenced earlier. "How important is the thermostat", it's not absolutely necessary but it will give you better / easier control of your seed starting setup. If you take the claims of 10F-20F above room temp at face value then a mat in a 65F-75F basement will get you in the sweet zone for pepper seed germination. In my experience (I have 3 mats) they throw off more heat than advertised in their hot zone. Case in point, my older analog thermostats probe went. I checked the temp of my Bhut/Scorpion/7Pot flat this weekend and it was up to 110F in the center cells and 98F at the ends. Room temp was 70F.

    If you do get a thermostat, I set my thermostat to 80F and place the probe in an end corner cell of a 72 tray flat. This seems to balance out all cells within a safe starting zone.

    Bill

    Here is a link that might be useful: Thermostat

  • User
    14 years ago

    Crap, it just struck me that I insulated rockguy was a cheapskate. Sorry rockguy, it wasn't my intention.

    If your setup works for you then more power to ya. I just know I'd screw up!

    Bill

  • tsheets
    Original Author
    14 years ago

    Thanks for the info, Bill! Much appreciated!

  • canadianchiliehead
    14 years ago

    I am about to pick one up.
    Lee Valley has one for $29 (9" x 19").

  • rdback
    14 years ago

    I too am a cheapskate.

    I bought a regular heating pad at Walmart 4 years ago for under 10 bucks. I set it on low and use varying layers of cloth towel between the pad and seed tray to dial in the temp. After that, you're good to go.

    A couple of other points:

    Although maybe not advertised as "waterproof", heating pads are at least "water resistant". If you look underneath the cloth cover, it should be made of plastic and appears to be sealed all the way around. If you think about it, they kinda need to be somewhat waterproof, for those occasional "liquids" one may accidently "spill" in the middle of the night.

    Also, be sure to get one WITHOUT the automatic 2-hour shutoff. They don't work for this purpose. Don't worry though, if you buy the wrong one Walmart will exchange it without a problem. Trust me, I know.(*smile*)

    jmo

    Rick

  • danasplants
    14 years ago

    you will find these matts are handy when rooting plants and all the seeds you want to do i have the expensive one. only because it was in a trade would use the one from Wamart with out thinking about it.

  • smokemaster_2007
    14 years ago

    Be carefull about spending the bucks on a thermostat.

    The heat pads are set to be 20 dgrees above room temp.

    A lot of people use their basement for starting their seeds or an empty bedroom or wherever.

    The room temp.there might be under 70 dgrees so your heat mat won't get over 80 or so.
    Peppers like 85 or so.

    In a colder room they wouldn't get up to 70 degrees...

    The thermostat I have only turns off and on the electric when the probe says it has reached the desired temp. it's set at.

    It would be useless for my use in a room where the mat only gets up to any temp. under 85 degrees.
    In my kitchen my mat only gets up to between 82 and 84 degrees.
    I'd only need the thermostat during the summer. LOL
    My kitchen isn't heated.

    So consider how the thermostat (and heat mat for that matter) you buy works and room temp. before spending the $$$$$.

  • User
    14 years ago

    smokemaster,

    Yes they are a bit pricey but I have three of probably the most popular mats (HydroFarm). Honestly, I'm not sold on the "increase by 20 degree above room temp" claim.

    I keep my house temp at 70F - 72F during the day and 60F at night in the winter (8F outside now). When my probe went on my thermostat the pads were on full time. My soil temp was hitting 110F. For a test I placed a food grade thermometer between two different mats and trays and temp was clocking in at 119F off the mats.

    Granted, 119F at the base doesn't mean the temp at the upper soil level will get to 119F due to ambient room temperature but it still gets higher than the advertised 20 degrees.

    I encase my trays in styrofoam to insulate against heat loss and evenly distribute heat throughout the tray (I find mats are hotter towards the wire end and center). Granted, the thermostat only turns on the mat for brief bursts but it does allow me to maintain consistent results at the temperature I require. Without it I would bake my seeds if using a mat. If I didn't use a mat then I'd never get to the sweet zone temp for pepper seeds.

    In my case (and in my opinion only) I find the thermostat a useful toll to help speed and increase germination.

    Bill

  • smokemaster_2007
    14 years ago

    Mine with or without the themostat does only go about 20 degrees above room temp. though your milage may vary.

    I know several people who sprout in their basements and have to insulate the sprouting space to get their mats over 70 degrees.
    They most of the time have to box up the whole thing.The heat mat raises the temp around the mats temp. probe or whatever regulates it's heat range so it basically would keep getting hotter until it burned out if they didn't have the thermostat hooked up.
    So i guess it's more what temp. the mat registers that matters.
    Which in my case is room temp.but for you is whatever temp. it reads from being closed in or insulated so it stays warmer.
    Mine gets moved around too much to box it or mess with insulating it to hold mat heat.
    One person I know said he got a 10 degree increase in heat by just putting foam under it.
    I'd guess a foam box that goes up to the sides of the seed sprouter would increase the mats heat even more by faking out the mat to think the room is a higher temp thus making the mat try to go 20 degrees higher than the temp. it thinks the room is.

    I was just letting people know that you might have to mess with the mats to make them do what you want them to do.

    Mine are Hydrofarm heat mats too.Only a couple months old.
    On sale for 1/2 price so I baught 2 for a little under $25.00.
    Thermostat was $24.00 and runs mats up to 1000 wats.

    They came with 72 cell sprouters and covers.

  • User
    14 years ago

    I'm understanding where you're coming from except for one point: "mats heat even more by faking out the mat to think the room is a higher temp" I don't think the mats have temperature regulators (I could be wrong).

    Up North it cost me $35+ tax for the mat/72 tray/dome and "1 mm plastic insulating stand (what a joke)". My electronic thermostat cost me $50 (tax included). We get screwed for most things even when the $ is near parity.

    Bill

  • cmpman1974
    14 years ago

    I think Hydrofarm misleads people. There's no way these heat mats exceed 10-12 deg over ambient temps.

  • tsheets
    Original Author
    14 years ago

    Wow! Great discussion! Thanks guys!

  • User
    14 years ago

    cmpman1974, I agree that their claims are misleading but I respectfully disagree with you on the direction.

    Just to check my own sanity, I filled up a tray with recycled ProMix, placed a new mat in one of my styrofoam boxes, positioned a thermometer on the mat, inserted the tray and plugged in the mat.

    After 30 minutes I checked the mat surface, soil and ambient temperatures. As you can see in the second shot below, the mat was reaching 123F (white thermometer), the soil temp (instant read thermometer) clocked in at 99.6F and ambient room temperature (grey thermometer) was 70F. IÂm sure if I placed a dome on the tray and let it go for an hour or two the soil temp would have reached towards 110F (the highest IÂve measured off of my other two mats).

    At least for me and my specific mats, I find the thermostat is the only way to maintain proper temperatures. It sucks to have to buy an additional component but it is what it is.

    Bill

    New Mat

    Various temps

    Bill

  • rockguy
    14 years ago

    Hi, my name is Rockguy and I'm a cheapskate. LOL. The water problem is partly the reason the plants are setting in a cookie sheet, the other is it helps distribute the heat more evenly. All my plant lights etc are running thru a GFI, AND YOURS SHOULD BE TOO.

  • User
    14 years ago

    Hi cheapskate,

    sorry

    Hi rockguy,

    Yes, I fully understand that the cookie sheet would offer both water protection and spread the heat evenly. As I said, I'm a klutz and I'd probably water the mat somehow anyways.

    Regarding Ground Fault sockets, YES. I've been knocked on my as# more times than I can remember messing with wiring. I have them installed in both my main level start area and my basement grow area. Didn't have them where I did my test today but no water used.

    I currently have three single mats. I figure I'll be two short when I start the bulk of my seed in late Feb. canadianchiliehead found a decent deal (at least up North here where crossing the border means 200% markup) for mats at Lee Valley. I may give the walmart mat / cookie tray a shot before dropping the dough at Lee Valley.

    Bill

  • cmpman1974
    14 years ago

    Thanks Bill. Is that 99 deg soil temp wet or dry?

  • User
    14 years ago

    Chris,

    It was dry. For full disclosure I hit the 110F temps on my previous readings (when the thermostat failed) when the soil was "moist".

    I'm curious... ok suspicious. I purchased my Hydrofarm mats as part of a Canadian distributors package labeled "Planters Pride".

    Given your and smokemaster's 10F-20F experience, I'm wondering if us folks up North are getting the reject mats? Could you or smokemaster test your mats like I did for comparison?

    Bill

  • smokemaster_2007
    14 years ago

    To test mine like you did I'd have to box mine in.
    If I can find a box big enough i'll put the whole mess in a closed box to see how hot it gets.Don't hold your breath.I work 14 hr days,7 days a week...
    I'm playing with LEDs now for grow lights and thats what takes up the time I do have that I'm not sleeping etc.
    Designing and soldering 1500 LEDs takes some time.

    Right now in the kitchen my mat will not go over 81 degrees and the kitchen is between 60-65 lately- the last few days.
    Right now the kichen is 63 and the mat is 81.4 degrees.

    Wether there is a temp. control or not in the mat itself boxing the whole thing up in foam makes ALL the heat go to the seed tray.
    No counter to heat or kitchen air to rob the mat of it's heat either.
    I think just putting foam under my mat would incrase the mats ability to heat the cells.
    My counter top is warm for a couple inches around the mat.
    It's all about sending the BTU's where you want them to go and cutting out any waste by not allowing any heat to go anywhere but to the seed trays.

    As far as wether there is or isn't a sensor in the mat doesn't really matter except as far as a fire hazard is concerned.
    The mats probably are designed to only put out a certain amount of heat no matter what.
    The more stuff it has to heat up and the colder that stuff is determins how hot EVERYTHING in contact with the mat gets.
    You are forcing your mat to be more efficient by boxing it in so of coarse you get higher temps.
    When they designed the mats I'm sure some tech figure out the min. and max. heat needed to get a seed tray in the temp. range they wanted using 70-75 degrees as an average room temp.as a standard temp.the mat would be used in.
    Maybe 100 degrees is the max that mat can heat to with the coils they made it with.
    Without looking it up I'd guess the wattage each mat is rated at goes up in the larger mats proportionate to the size of the mat.

    It's been raining with 50 degree highs during the day.
    Some one must have sent some cold weather seeds to me along with the pepper seed trade.
    We aren't ever this cold for so long in winter.

    I don't think our mats are different,it's how they are set up as far as directing the heat where we want it to go.
    I do nothing but set my trays on it where others box them in,put foam under them,put towels over the whole thing etc.
    It's all about sending the heat to the tray and elliminating any waste.

    Thats my story and I'm sticking to it.

  • rockguy
    14 years ago

    Back at the dawn of my gardening, I used an upside-down cakepan with an incandescent bulb under it for a heat mat for peppers. 25Watt IFRC

  • User
    14 years ago

    Oh sure smokemaster, destroy my "reject mats" conspiracy theory all to hell by using logic. Curse you ;-))

    Yes it makes sense that some of the mats energy would be absorbed by the surface it is sitting on. Styrofoam = low absorption vs. metal table = higher absorption. So I guess, as you pointed out, the mats would be engineered to perform best the way they are most commonly used; under an open tray on a kitchen counter or table. Just for fun, another test or two is in order. I'll post some results later today or tomorrow.

    BTW, when I purchased my first mat kit 4 or 5 years ago it came with the styrofoam box shown in my pictures. Back then I didn't measure the temp or use a thermostat. Surprising I got any sprouts at all! The same kits today come with a so called "insulating stand" that's basically the same design as the styrofoam box but it's made of the same thin plastic the tray cells are made of. It can't really support a watered tray let alone provide insulation. Marketing, too funny.

    Since my original purchase I've made crude tray boxes (photo below if anyone's interested) out of styrofoam for additional mats. I have found that the mats have warmer and cooler sections. By using the foam boxes I get a more even heat distribution through the tray, no cooler cells around the edges. I guess it may be the reason I need a thermostat.

    Later,

    Bill

  • smokemaster_2007
    14 years ago

    Your mats could be made by Aliens though using some unknown space tech.
    I know 1 of my plants looks like it's growing in soil from outer space.(Blue and red LEDs). LOL

    My mats came with a tray,cell tray and a clear cover,no foam.
    I spotted some of that green insulation foam at work yesterday.
    It might become a box when I have the time.
    Darn you guys.
    Now I gotta play with 2 toys at once...

    As a frame of reference.After reading the cautions written on my heat mat sheet I took some silicon chaulk and put a little around the heat sencer where it meets the wire so water wouldn't get in if the stuff they use failed.
    (I wasted a remote BBQ thermometer by getting meat juices in the probe once).
    It was almost cheeper to buy a new unit than buy a new probe with shipping cost added on.

    NO I didn't woose out and read the instructions on the mat.
    WE DON"T NEED NO STINKING INSTRUCTIONS.They are for wimps to read,not real men. LOL

  • User
    14 years ago

    Instructions? That must be what that writing on the mat is, go figure.

    As for Alien technology, nah I donÂt think so. The guy I bought it off of looked like a bit of a freak but he didnÂt have any feathers like all the other aliens IÂve bought stuff from in the past.

    OK, without further ado, here are the results of my totally unscientific tests (geeze I gotta get a life).

    I will note that my current start trays have settled nicely to 85F center and 79F-80F at the edges. They are in Styrofoam boxes and the mats are being controlled by a thermostat set to 85F with its probe in a center cell.

    IÂll leave it folks to interpret the results for themselves. While youÂre pondering them IÂll leave you with one last thought:

    "The fact that we live at the bottom of a deep gravity well on the surface of a gas covered planet going around a nuclear
    fireball 90 million miles away and think this to be normal, is some indication of how skewed our perspective tends to be."

    (Douglas Adams 1952-2001)

  • cmpman1974
    14 years ago

    I'm sold on your theory Bill. I've played around yesterday building a larger styrofoam box to fit my 48" x 20" heat mat. In a 65-67 deg basement, I'm getting temps around 83-84 now in the soil. A probe put between the heat mat and botom of seed trays reads 115 deg. I don't think I have the patience to conduct your table experiment. lol.

    My conclusion is these Hydrofarm manufactuers need to spare a few bucks and include a decent styrofoam container for us U.S. buyers. Cheapskates. lol. The $70 price tag isn't enough to include $2 in styrofoam? Geez..

  • User
    14 years ago

    Hi Chris,

    Nice to hear you found the information useful.

    I'd appreciate if Hydrofarm also included a decent container for us folks in Canada too. As I mentioned above we just get the cheap plastic one now. It has the insulation properties of one ply toilet paper ;-)

    I may spring for a cheap can of spray foam insulation and try to salvage the two I have.

    Bill

  • User
    14 years ago

    Just to beat a dead horse and kill some time on a lazy Saturday afternoon, I though IÂd post some shots of the cheap plastic "insulating" stand IÂve been referencing.

    Kind of hard to get the fine detail on the black object (IÂm too lazy to pull out proper lighting equipment), but anyone interested should get the gist of what I was referencing.

    HereÂs the stand ready for a seed starting tray.

    HereÂs a shot of the top and bottom. The white arrows are pointing to where I was thinking of filling it with spray foam insulation. If anyone got these tray stands as part of their mat kit, the spray insulation may be less messy that cutting and gluing styrofoam.

    FWIW

    Bill

  • smokemaster_2007
    14 years ago

    Watch out for some of the spray on EXPANDING foam stuff.
    We use it for motorhones and different brands are different stuff.
    Some melts plastic,some keeps expanding for a LONG time after you think it's set.
    Read the cautions(not instructions-those are for wimps)about exposure to different stuff.

    I broke down yeaterday and made a box out of the foam sheets they ship our motorhome parts in.
    Didn't want to mess with the green stuff until I tested out the free/cheep stuff.
    Temps today are at 85.
    You'll see that all I basicaly did was stop heating the counter top.

    {{gwi:1141405}}

    {{gwi:1141407}}

    Put together using toothpics for nails.
    Went together fast.Took longer to clean up the darn foam scraps that were all over the place.

  • cmpman1974
    14 years ago

    Bill, I just whipped this new arrangement together this afternoon. I love it. It's really doing the job now. A BIG improvement in ability to hit desired temps! It was a mess to clean up as Smokemaster stated. Lots of vacuuming.

    {{gwi:1141408}}

  • smokemaster_2007
    14 years ago

    Looks like the nails did all right.
    Who needs glue. LOL
    Keep those little guys nice and warm.
    Foil lined foam probably helps too.

    I'm still finding the stray balls of foam stuck to stuff by static electricity.

  • User
    14 years ago

    Hey Smoke and Chris,

    Nice jobs. I like the nail and foil lining ideas.

    Smoke, thanks for the heads up on the spray foam. Got it, note Cautions and We Don't Need No Stinking Instructions.

    OK folks, next weeks project: Improving your satellite reception using styrofoam.

    Bill

  • smokemaster_2007
    14 years ago

    Satalite reception?
    Doesn't that require a tin foil hat to safely work on?

    Is the foam for cushioning?
    I know putting corks in your ears helps to keep your brain from dripping out when you sleep on your side without your foil beanie.

    Here is a link that might be useful: Foil hats

  • greengrass12
    14 years ago

    I think heat in general is much more important than bottom heat in the pepper germination world.

    Last year I put a 18w bulb over 3 6 packs of peppers and enclosed it loosely with tin foil. White habs up in 6 days and the first orange and choc habs up in 10. Maybe the 10 days can be reduced by 2 or 3 but the extra couple days don't seem worth the expense of buying thermostat with pad. It would be a different story if germination were taking 3 weeks.

    This year I am going to put a heating pad in enclosed mini greenhouse to see if I can get a more even germination. A pretest shows that ambient temp in the greenhouse gets up to 78 deg and the heat pad itself registers about 110 deg. I am going to ut some styrofoam on bottom as suggested here. The heating pad was made to use with moist cloth so I guess it's waterproof against the little bit of water that might trickle onto it. I have a cheap timer to run the heat for couple hours and off for 1/2 hr.

  • User
    14 years ago

    Yep, doesn't matter where the heat is coming from; top, bottom or sides as long as the seed location reaches the appropriate temp. It also doesn't matter if heat comes from mats, light bulbs, rubbing two sticks together, etc.

    I've read other posts/articles about using timers to control temperature. Let us know how it works out.

  • seysonn
    10 years ago

    Thanks to otawapepper for providing the link to this thread.
    There are a lot of good useful and lively discussions. I will have to go back and read them all.

    What I benefited from the discussions so far:
    == Thermostatic control can save lives(i.e seedlings).
    == Styrofoam can extend your mileage, Together with thermostat, of course.
    == I am looking into cmpman's desing, that could cost just a buck or two. Still need styrofoam thou. Plus making the design water proof.
    Well, I've got plenty of time to work on it. About 3 months.

  • User
    10 years ago

    seysonn,

    Glad you found the link useful.

    Not sure why you say Plus making the design water proof,.

    The foam boxes aren't intended to hold a seed starting medium directly. The boxes are meant to hold non-draining starter trays and inserts like the ones from Amazon pictured at the end of this post.

    If you're into the damp paper towel in a baggie germination method, a friend had great success last winter sitting the baggies in the plastic tray (see below) on top of the heating pad with the thermostat probe on top and covering the styrofoam box with another piece of styrofoam on top. Basically an insulated incubator.

    Bill

  • seysonn
    10 years ago

    Hi Bill. Thanks again.

    My comment about water proofing meant to be about cmpman's method using regular light bulb as heat source. So I dont want the water to get on the bulbs. I may also visit the drugstore and look for shoulder heating pads, if the stuff is cheaper. I can germinate my peppers first then do the tomato seeds after that. I have a 48" shop light wit two T8 tubes. I might get another one to hang side by side, if needed. Costs about 20 bucks with the tubes.

    No. I am not into germinating in paper towel and coffee filter in plastic bags. I have tried it before. It works but just too primitive. I want to do it like the REAL pepper growers , like yourself , do it. LOL

    INTENDED GERMINATION SET UP

    Another Thought: How about germinating on the top of the shoplight. Got to make a water proof tray that just barely touching the shoplight but not sitting on it. I will do a pilot teast to see how it works.

    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Added ^^^^^^^^^^^^^^^^^^
    I am monitoring the temperature on top of shoplight ( w/ two T8 tubes) Direct contact temperature stabilized around 105F, at them room temperature of 72F. I figure with a tray (almost touching it) cannot get any hotter than 85-90F. I can always cushion it to lower temperature the

    This post was edited by seysonn on Fri, Oct 25, 13 at 2:17

  • rootlady65
    10 years ago

    seysonn

    you just gave me a new idea for my seed starting. I have grow lights hooked up for my plants. I never thought of rigging up a shelf thingy above my grow light. I have a shop light fixture and my house plants love it.

    Also, I'm using one of the double shelf hanging racks that you would use in your garage. Set one self slightly above the other. I was supposed to use both shelves but n ever hooked up the second self. Good thought hope it works.

    Here is a link that might be useful: GardenWeb

  • tomt226
    10 years ago

    Here's a germinating/new growth box I've used for several years. Just a ply box with 3/4" insulation and a galvanized steel flashing top. Change the bulbs out for different temps. Details if ya'll want'em.

  • seysonn
    10 years ago

    I went to Walmart today and checked their heating pads.
    As, mentioned here, they have two kinds : One with 60 min. auto shut off and the other 24 hr. shut off. Logically, I bout the second one. with the tax it cost me under $20. It is 15" x 20" and has three settings : LOW, MEDIUM, Hi. I am testing it right now. The LOW settings seems to be enough. The temperature under the pot gets up to 95F. With some extra padding, I control the temperature around 90F . I will check the soil temp in a little while. For small scale germinating it should be just enough. Whats more, is that can use it medically. LOL

  • jutsFL
    10 years ago

    Got this one on Amazon for like 9 bucks, works very well too. Made by Millard.

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