Warning! Seedling Mat Temperatures

[hotrodharley]

It's -32F here right now. Standard winter. So I bought a heated seedling mat. Literature says it operates from 70-85. Tops of medium drying kind of quick with the tent 72F.

Took my Fluke Infrared and shot the temperatures of everything. Mat 86-92F. Cups 77 halfway up.

And they advise using a dome? FYI. Vivosun 20"X20" model.

 

[Herb & Suds]

I always place a bath towel over heat mats
Evens the hotspots out

 

[hotrodharley]

I always place a bath towel over heat mats
Evens the hotspots out

That's exactly what is under them now and guys - the touch test fails here. I think an actual quantum PAR meter, an EC meter and an infrared are invaluable. All affordable.

 

[shnkrmn]

you are supposed to take the dome off as soon as the seedlings emerge. The mat is just to speed germination.

 

[hotrodharley]

I'm well aware of what it's for. That's why it's here. Again this is for people who can't check. The printed information is way off. Easy enough to remedy.

 

[Herb & Suds]

That's exactly what is under them now and guys - the touch test fails here. I think an actual quantum PAR meter, an EC meter and an infrared are invaluable. All affordable.

I put them under and above

 

[shnkrmn]

Sorry. You called it a seedling mat. Thus my error.

 

[hotrodharley]

Sorry. You called it a seedling mat. Thus my error.

I'm glad you said what you did. A lot of people read these after we're done here. I was just surprised at the disparity. If someone didn't know they could cook them. @Herb & Suds advice will be standard with me from here on.

 

[shnkrmn]

I have 3 mats. Because come March I go crazy for veggie gardening. I think one of them is vivosun. I wonder if they are uniform in heating but not enough to investigate. They definitely help sprouting but, yea, you can cook babies pretty fast if you leave them in there. It would be like sous vide for baby plants!

 

[CWF]

I'm using an inexpensive temp controller (PID) to control mine exactly. I also use it to ferment bread doughs and such. Hydrofarm mat.

 

[hotrodharley]

I'm using an inexpensive temp controller (PID) to control mine exactly. I also use it to ferment bread doughs and such. Hydrofarm mat.

I have an Inkbird. I think I'll stick the probe under this setup. I just received this thing. Seeds are sure popping!

 

[CWF]

I use a wire rack over mine to keep stuff from directly sitting on the mat, and a piece of foil and styrofoam building insulation under it. Temp probe also sits on the rack. When I raise dough or sourdough starter, i put an insulated box inverted over it.

 

[Manipulator]

I use a wire rack over mine to keep stuff from directly sitting on the mat, and a piece of foil and styrofoam building insulation under it. Temp probe also sits on the rack. When I raise dough or sourdough starter, i put an insulated box inverted over it.

 

[Jjgrow420]

I never use a heat mat without a controller. If the surface it's on is too cold it'll heat too much.(that's why they say not to put on concrete floor that's cold) If it's too warm (ambient) it'll heat too much. Generally they say the mat will heat about 10° higher than ambient temp. If your rooms 72 then it's gona heat you up too much. Controller is key. I put the probe inside a cube and put it right beside the cuttings or seedlings. That way I get an accurate reading of the plugs temp.
If you just hang your probe in the top of the dome it'll heat the hell out of the bottom to get the top to the temp you set. Or never be able to reach it and continue to run until you've deep-fried your plants. I'll put a tray of water then my tray in that tray. The water buffers the temp and keeps it from swinging while maintaining temps and not cooling and heating constantly.
I duno that's how I do.

 

[LeastExpectedGrower]

I have an Inkbird. I think I'll stick the probe under this setup. I just received this thing. Seeds are sure popping!

I've got a handful of the vivosun mats and a couple of their controllers. Makes sense that they'd run hot down low to me...part of that is getting the sensor placed right. I like to fill a 'dummy pot' and bury the sensor about 3/4ths of the way down into it. I've also put it under the pot, but I think you don't get the temps you want at the top of the soil that way.

I set mine to about 78 and run it for germination and the first week after that.

 

[Jjgrow420]

Ya depends what my ambient room temp is. If it's in the 70s I'll set at 75-76 if it's in the 65ish area I'll set at 77 or 78.

 

[hotrodharley]

I've got a handful of the vivosun mats and a couple of their controllers. Makes sense that they'd run hot down low to me...part of that is getting the sensor placed right. I like to fill a 'dummy pot' and bury the sensor about 3/4ths of the way down into it. I've also put it under the pot, but I think you don't get the temps you want at the top of the soil that way.

I set mine to about 78 and run it for germination and the first week after that.

Damned good idea!

 

[myke]

Just put a shelf above your veg light,plenty warm there.No use paying for more electricity.

 

[xtsho]

Just put a shelf above your veg light,plenty warm there.No use paying for more electricity.

I use the top of my T5.

 

[rkymtnman]

It's -32F here right now. Standard winter. So I bought a heated seedling mat. Literature says it operates from 70-85. Tops of medium drying kind of quick with the tent 72F.

Took my Fluke Infrared and shot the temperatures of everything. Mat 86-92F. Cups 77 halfway up.

And they advise using a dome? FYI. Vivosun 20"X20" model.

hey hotrod, could you put a pic of yours up? i'm wondering if all these mats are from the same shop iin china? i do like herb and suds does and put it between a bath towel.