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Pedro99

Seedling heat mat

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Hi everyone, 

Just after suggestions for seedling heat mats.. I sowed some loph seeds a while back using takeaway tek and due to the cold temps they haven't germinated. 

 

They still may be viable if I heat them maybe. I also just received a bunch of trich seeds and they would probably also benefit from warmer soil. 

 

If I were to sow all the seeds plus the 2 containers I have the lophs in I would have around 8 takeaway containers so I may either need a larger mat or two of them. 

 

Just don't want to buy a dud..

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how's the temps inside ? in winter I sow seeds inside under a couple cfls in a room with a wood fire 

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Hi Matt, 

Temps inside can drop to maybe around 12, but average about 18 at night I don't use a heater just wrap up in a blanket. Am in qld so it's not too cold though. 

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lining a box in foil and putting it all in that might help keep it all warm, honestly though heat mats aren't too expensive just be sure you can control the heat, and check to see how warm it gets before putting it under the trays, wouldn't want to cook the seedlings 

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Posted (edited)

I think I can help. It took me a few goes to get the takeaway tek to work in the middle of winter. First time I only got 1 seed to sprout but then I figured it out and now every time many of my seeds sprout (lophs, ariocarpus, ortegocactus, mamilaria, trichs, ect).

 

This is what I've found is critical:

- Light source in the right spectrum and at least 5000 lux.

- Heat mat, low 20's celcius are a minimum.

- Timer for heat mat and light. (I set to 12 hrs on 12 hrs off but more or less should work fine.)

 

Details:

Cheapest and best bang for buck for the right light spectrum is a warm white LED bulb. You can use compact fluoro in warm white which are slightly less efficient. You can also use halogen in warm white but they are much less efficient (lots of the power ends up as heat). Put the bulb in a cheap adjustable desk lamp from Bunnings or supermarket. I find the lowest 6 watt LED bulb is great for just a few cactus seedlings in tupperware containers. When I have a small coffee table with full of 6cmx6cm potted cacti on it and the tupperware seedlings during winter then I use an 11 watt LED bulb and raise it up so it hits everything.

 

The most critical thing and the deciding factor between me getting only 1 seed to sprout the 1st try and then getting most to sprout the 2nd try was getting the bulb at the correct height to get 5000 lux. I did not use any fancy light meter. I just downloaded a simple free sensor app on an android phone. Most phones made in the last 10yrs running android will work fine as they have a light sensor for auto adjusting the screen brightness for indoors & outdoors. Many free sensor apps will show you a reading of light measured in lux. I stick my phone right on top of the lid of the tupperware containers with the seeds and make sure I'm getting at least a reading of 5000 lux. If you go heaps more than 5000 lux keep in mind that your seeds should still sprout but the seedlings can get a red spot from "light burn". If this happens just move the light source back a bit.

 

I got the the desk lamp, warm white LED bulb & timer from Bunnings for cheap.

 

The heat mats I used are the small camo $5 USB Heat Mats from ebay.com.au bought directly from China. Here's a link:

Been using for over a year now with no problems. https://www.ebay.com.au/itm/Pet-USB-Electric-Adjustable-Heat-Pad-Reptile-Heating-Mat-Warmer-Blanket-AU-Stock/254140829651?hash=item3b2bf94fd3:m:maxmf2twD4v-DStMmFlPyeg

Keep in mind that I found the model of these that work with a separate timer is the USB heat mat with no switch or adjustable heat settings. I wouldn't reccomend buying the mat that has the switch and adjustable settings as it won't turn back on automatically with a timer. I'm not an electrical engineerd but my 2cents are that if buying a heat mat from China I'd go with one that does not have an internal AC to DC power supply (no wall plug). That is why I just got a simple USB powdered heat mat. For the actual AC to DC power supply (AC wall socket to USB) I use a proper name brand phone charger such as Sony or Samsung. Any proper name brand phone charger rated at 2 Amps output @ 5 volts is sufficient for one of those small mats (My testing shows the small mat draws 1.35 Amps). Dunno how much current the medium size mat needs to reach full heat but I'd expect more than the small. So if you get the medium size mat and it's not getting as warm as it should you may want to try it with a larger current phone charger just to check that it's getting the full current it wants. You can try it with any chargers you have that are more than 2A output and compare with the 2A charger and see if the mat gets any warmer. The mat is current limited (will not draw more current than it needs) so you can safely use any USB charger that is rated to more output current than it needs (3A, 4A, 5A, ect). Just make sure the USB charger says 5V output and no more. Most are 5V. I use a simple USB plug in device with a small LCD screen that I can plug any USB device into and it shows me exactly the voltage and current it is drawing. The are only 5 bucks from ebay. Here's a link if you want one: https://www.ebay.com.au/itm/USB-LCD-Detector-Voltmeter-Ammeter-Power-Capacity-Battery-Current-Meter-Tester/322629753120?ssPageName=STRK%3AMEBIDX%3AIT&var=511633953564&_trksid=p2060353.m2749.l2649

 

621949398_HeatMats.thumb.jpg.340cf00e014ce38902c8a22c4bf313d8.jpg

 

 

 

 

 

Here's a pic below of some of my cactus seedlings using the takeawak tek. I'm using the small size camo USB mat l linked to above. As you can see the max it can fit is 6 of those small cube tupperware containers that you buy from k-mart.

279793372_Dsc_0696-Cropped.thumb.jpg.10fd3c01262298601e8c56313a72a1f5.jpg

Edited by Raver Buddy
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Posted (edited)

Yeah in my experience it helps, brings temp from 20 to 30 here using a terrarium stone with a book in between as buffer..

 

Supposedly it is best to turn it off at night or at least have fluctuations.. not sure how confused the seeds get if you were to not sync the warmth with the light...

 

Of course you can also get more evaporation and mold etc with heating. So be careful and have the life in the soil stabilized if you can.

I think you are better off just growing at about 18h of light per day instead of 12, but yea you can put the heating on 12/12 that should be fine.

 

About the light spectrum: certain proportions of far red vs red wavelenghts can promote stretching in plants and it is generally thought that red light (vs blue wavelengths / the rest of the spectrum) can too... but on the other hand a warm spectrum does promote good growth of roots.

 

Probably not a good idea to overfocus on what spectrum temperature you pick but the exact composition of the spectrum can vary even between ones of the same temperature and there should be a decent balance and no major deficiencies is IMO key. Other than that i believe in dual spectrum.

 

That said, i'm talking beyond the seedling stage and you can just use a 6000K fluorescent tube for seedlings and it works perfectly for me. 2x36W is nice... when you see that subtle purple blush you know you are on the heavy side of good.

 

Your seeds should germinate with the extra warmth... but if even that doesn't help (i think about 75% is reasonable for species like in Lophophora) there are ways of inducing germination like GA3 or you could try karrikins / smoke water for some plants. However that may not work for cacti since they are not used to growing after a forest fire lol. So it would have to go way way back on the evolutionary timeline.

Edited by Solipsis

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Posted (edited)

Okay m8. If you wanna get technical on light for indoor growing of cacti this is the best Youtube vid-jay-oh I based my tech off. It's from somone @ Cactusinfo.nl:

https://youtu.be/r30oZ3FoAAs

 

His quote is:

Quote

"The light emitted by a warm white LED lamp is favourable for both germination & growth"

 

 

Also just incase I didn't make this clear before, the reason I went with a simple USB heat mat from China and NOT one from China off ebay that contains it's own power supply is because of SAFETY. I've seen a bunch of electrical engi-nerd Youtube vid-jay-ohs of cheap Chinese AC-DC power supplies where they are not up to Aussie or UK standards. Often not with proper gaps between the high voltage AC side and the low voltage DC side. You only have to see some teardowns of fake knockoff Apple or Samsung USB chargers to get an idea. Now you might be thinking but it's all made in China well the difference is as far as I know even cheap shops here like Bunnings, Woolworthless or Reject Shop that get their electrical stuff made in China have to be up to Aussie electrical codes. Buying from ebay either directly from China or from a fly-by-night Aussie ebay reseller, gets around this. The worst case I've seen is where a USB charger failed internally and the full 240V from the AC side crossed into the the low 5V DC line. Needless to say the comment was it gave someone a rude tingle when they touched it so they sent it in for a tear down vid by an electrical engi-nerd!

Edited by Raver Buddy
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I'm off grid so I just put mine on top of the inverter, or hot water system, even some fridges get warm on top. Not exactly high tec but it works. Mind you its not real cold here.:scratchhead:

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On 14/07/2019 at 6:46 AM, Raver Buddy said:

Here's a pic below of some of my cactus seedlings using the takeawak tek. I'm using the small size camo USB mat l linked to above. As you can see the max it can fit is 6 of those small cube tupperware containers that you buy from k-mart.

279793372_Dsc_0696-Cropped.thumb.jpg.10fd3c01262298601e8c56313a72a1f5.jpg

Your seedlings need much more light and you need to open those containers

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