jiffy pellets a must! and yea ditch the heat may haha
youāll thank us later
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May I propose an experiment?
Leave your seeds in the dome in paper towel as they are, and put them somewhere like the top of your fridge. Somewhere warm-ish
Meanwhile, plug in your heat mat, put a dinner plate on top of it, a wet paper towel inside, and another dinner plate on top.
Place the thermometer probe, or the tip of a cooking thermometer, or the body temp thermometer, between the two plates. Check the temperature in one hour. Or if you have an infrared heat gun shoot the paper towel in one hour.
If it is over about 28-29C it is not ideal. If it is over 30-31C it is deadly.
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Idk how to change this thing to Fahrenheit 
āhey Siri, convert this shit to Fahrenheit plzā 
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Take the Celcius temperature, multiply it by 1.8, and add 32 
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Iām goin with the pellets and the dome is on the fridge. Testing the heating mat now. That would suck if itās too hot! I got it specifically for seedlings hoping to have better success than the last time I ruined 40 million seeds 
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Aw snap thanks, good to know. Iāll still let Siri handle the math unless my phone is dead tho
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If things are a little to warm with the mat you can put a buffering material like cardboard 1/2 layers and then your tray on top should help a bit!
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I like to check my mat with a small glass of water and a simple meat thermometer leave it on for awhile to get a stable temp for checking.
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Probablyā¦put a thermometer in there. 
(If I use my seedling heat mat and a dome, without a thermostat, it roasts plants.)
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When I first got a mat, I assumed that because it is a seedling mat, it had to be plug and play. I cooked both seeds and clones. I tried raising the seeds higher off the mat. I even made a power control (a dimmer switch), to keep the temps in line. I tried a timer. I spent a lot of time and energy trying to avoid buying a thermostat. When I finally gave in and decided to buy a thermostat, it was between $15-20 at Amazon.com. I got almost instant success from that.
Those mats have no circuitry. There is a tiny little box where the cord connects that uses resistors to control the temperature. Wall current varies throughout the day and night causing peaks and drops. Room temperature makes a huge difference. The thermostat has intelligence built in. It reads the temperature of the mat and compensates as needed, despite external factors.
Trust @Scissor-Hanz and me, get a thermostat, save some seeds. 
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Nice explanation! Iāll look into that thermometer. Spent like $400 the past month, and even ten bucks today, on amazon on shit for my tent, so Iām gonna do the prop dome on top of the fridge for this round of sacrifices (seeds) lol. Thank u!
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Just now realizing that I did this experiment wrong. I suppose I need to see how hot a wet towel gets, but Iām not sure if I have a thermometer for that.
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Not at all, you did great. This just showed that the mat doesnāt care ā it got to 37, which will cook your seeds. I think they just took a heat mat and re-branded it as a āseedling heat matā. This thing needs a thermostat. It would probably get even hotter if you had plates on top.
Now you know, and the seeds on top of the fridge are safe from the excessive heat 
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I would keep your heat mat , handy for cuttings etcā¦
Donāt toss it , put it away til you have a need for it mate ā¦ ( just saying).
Happy growing/smoking ,
Gaz
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Here is a setup I have with a $7 eBay temp controller.
The power is wired to the controller and out to the mat. The probe is inserted into an extra rockwool cube, watered the same way as all the others, so that it āfeelsā what a clone, or a seed would.
Not pretty, but works well
Keeps temp within 2C or so
And cheap as borschā¦
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Thanks for the advice, Iām glad Iām not cookin seeds anymore lol. The ones I had on the heat mat turned to white mush on the inside 
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At the very least Iāll save it for winter when my old house freezes over and Iām getting hypothermia in the middle of the night lol
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Hey it looks like a good set up to me! Iām gonna work on it. The current seeds are gonna have to rough it in the dome on top of the fridge for now tho lol. Ordered some jiffy pellets that should be here tomorrow so hopefully grow #2 gets goin!
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Top of the fridge or cable box are two spots I like to germinate in cold months (not many here). 
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