Being winter now, all I can think about is heat. This naturally made me think of the best ways to keep your seedlings growing well during this colder season. Seed germination requires warm temperatures, and those are hard to come by right now.
Seedling heat mats are the best way to keep your seeds at just the right temperature required for germination. What is the best temperature for cannabis seed germination? It can vary widely based on the particular strain, but generally you want to stay between 70 and 90 degrees F. (21-32C).
A standard heat mat will just plug in and heat up, maintaining a pretty wide heat band of 25+ degrees. This is obviously too much swing for the safety of your precious plants, so you should probably look for a heating mat that has temperature control.
Advanced Seedling Heat Mats
There are heating mats available today that come with digital thermostats and temperature probes to give you much more accurate heat control. These kits consist of a thermostat control box, which allows you to set your desired temperature, and a remote temperature probe.
Also on the box is a standard 3 prong outlet. This is where you plug on your heating mat. You can use any size mat on the thermostat controller. Simply choose controller and the size of mat that you need and voila! Some manufacturers, like Mars-Hydro and Vivosun offer kits that have the controller and a mat in 1 package.
Choosing the right size seedling mat
The size of your mat is directly dependent upon how many seedlings you plan on starting at one time. If you are only growing 5 plants, there is no need to buy a large mat. The exception to this is if you live in a cold climate, or your grow location is in a cooler place, like a basement.
We have cold winters here in Colorado, and my grow is located in a basement where it is always colder. The floor stays cold all year, so I line the bottom of my grow tents with these heat mats. They help to maintain an even temperature inside the tents and keep the bottom of your containers from getting cold.
Controlling the temperature
For some plants, it is vital for them to stay in a very small temperature range. Without an accurate thermostat, you risk damaging your seedlings. Different brands can vary as to the temperature swing in their products, so it is important to test them.
The best way to test your heat mat’s temperature is to use an IR heat gun. You will need to set your desired temperature, load up the mat with some seedling trays, and let it run for 24-48 hours. It may take a little longer depending on the ambient temperature and the temperature goal.
After 24-48 hours, its time to take the temperature. Using your Infrared thermometer, take a reading from multiple locations and see how far off that is from your set temperature.
If I know that my thermostat is set to 75, and the real temperature is 71, then I know I need to boost the setting by 5 degrees to compensate. It’s best to take your time here; getting your thermostat dialed in will make your growing much easier.
Alternative Uses
You can also use these type of heat mats if you grow mushrooms, or would like to try to grow mushrooms. These heat mats excel in this environment, where very precise temperatures are needed. We use grow tents with plastic shelving inside (4×2 grow tents are best suited for this), with one of these mats on each shelf.
These mats are also great for anyone brewing Kombucha, making yogurt, or similar things that require precise temperature control over long periods. These also make excellent heating mats for reptile enclosures.
I am sure that there are lots of other scenarios where these waterproof heating mats could be used, so we won’t discuss them all. The point is, these mats are pretty versatile, making their relatively low cost very attractive.
Where to buy heating mats
There are a few places online where you can buy a seedling heat mat with a digital thermostat. I have used heating mads from Mars-Hydro and Vivosun and both have been working quite well. You can read our reviews of both of these company’s products below.
There are other brands available on Amazon that we have not tried, so I will not vouch for any of them. Feel free to do your own research on them at your leisure. We have more manufacturers being added to this list soon, so be sure to check back.
Click here to read our review of the Mars Hydro Seedling Heat Mat Digital Thermostat Combo
Click here to read our review of the VIVOSUN Seedling Heat Mat Digital Thermostat Combo
VIVOSUN Seedling Heat Mat Digital Thermostat Combo
VIVOSUN has been around the growing game for quite some time, offering good quality products at low prices. They have a dominant presence on Amazon, and for a good reason. The products are built well and not overpriced. VIVOSUN products are perfect for the beginner grower who needs a lot of stuff with a small budget.
The VIVOSUN seedling heat mat with digital thermostat is an excellent cost-effective heat mat for anyone interested in growing. They come in 5 different sizes to better fit your individual needs. The mats help maintain temperatures of around 10-20F above the air temperature in your location so your seedlings have a better chance of growing strong.
This heating pad uses advanced far-infrared heating technology to provide consistent and even heat; This technology expands the heating area in order to create more optimal conditions for accelerating plant growth; The durable, reinforced heating film comes with double insulation to ensure that the heat will not scorch the roots.
The Controls
This model uses a remote temperature probe designed to act as a thermometer in a separate location. This allows you to keep the controller in a viewable location while monitoring the temperature up to 3 feet away.
When the heating mat is in an environment with temperatures ranging from 20-25℃ (68-77℉), it can heat up to 40℃ (104℉) in a few minutes by radiating far-infrared light waves; The maximum temperature setting is 122℉, and it includes built-in overheating protection that automatically powers off the pad when the temperature is too high.
Accuracy
We tested the accuracy of the digital thermostat controller to see how accurate it was. For our test, we placed a plastic tub with a 3-inch layer of cocoa coir on top of the mat and placed this all inside a grow tent. The probe as inserted into the center of the tub, half way into the coco.
After waiting 48 hours for the temperature to stabilize, we checked the temperature with both a calibrated digital thermometer and an IR temperature gun. The temperature, while being very consistent over the course of 48 more hours of temp checking, was off by about 3 degrees.
As long as you are not working in the upper range of the pad’s limitations, this is not a really big deal, we just know to set it 3 degrees higher than we need. If you insist on pinpoint accuracy, you may need to look elsewhere. That being said, every seedling heat mat we tested suffered from 2-5 degrees of inaccuracy.
Quality Check
The VIVOSUN seedling heat mat with digital thermostat controller is well built. Its made of durable PVC and PET film designed to meet MET standards. Far-infrared heating technology facilitates better resistance to high pressure. The IP67-rated waterproof surface is safe to scrub and helps keep the device clean and functioning properly.
Even Heating in a Larger Heating Area: This heating pad uses advanced far-infrared heating technology to provide consistent and even heat; This technology expands the heating area in order to create more optimal conditions for accelerating plant growth; The durable, reinforced heating film comes with double insulation to ensure that the heat will not scorch the roots.
Overall Impression
We have been very satisfied with the VIVOSUN Seedling Heat Mats. They heat up quickly and can hold their temperature very well. The mat took a while to flatten out after unrolling; it was pretty stiff. After turning it on though, everything flattened out nicely.
There was a minor issue with the control interface. While the interface is nice and simple, we found that the “Down” button on our controller was not working properly. I took the controller apart to see what the issue was. I found that there was a wire that was pinching against the push pin, impeding its movement. A quick adjustment resolved this issue.
Despite this minor issue, we are still impressed with the VIVOSUN Seedling Heat mats, and have no problem recommending them to anyone in need. The mat comes with a 1-year warranty, so if you have any issues you can get it replaced.
If you are a beginning grower, or are just looking for a digitally controlled heating mat in general, check out VIVOSUN to find the right size for you!
Mars Hydro Seedling Heat Mat Digital Thermostat Combo
If you are looking for a player who has been in the grow game for over a decade, look no further than MARS-HYDRO; They have consistently supplied high quality hardware at an affordable price. The Mars Hydro seedling heat mat is no exception. This Mars Hydro seedling heat mat review will tell you all you need to know.
Unlike cheap electric coil-based heat mats, The Mars Hydro seedling heat mat uses far-infrared radiation heating to provide a gentle and consistent warmth that is maintained to your needs by a digital controller. This helps to maintain heat much more evenly in your trays.
The Mars Hydro Seedling Heat Mat is a high-efficiency heating mat, outputting 105Watts. The high-quality carbon fiber inside helps this mat to achieve heat conversion efficiency of up to 97%. This helps to produce a more even and stable heat area. The mat can achieve temperatures up to 48℉ higher than the ambient air temperature.
The Controls
The controls of the Mars-Hydro Seedling Heat Mat are simple and straight forward; There are only 3 buttons and a display. The buttons allow you to quickly set your desired temperature as well as toggling between displaying your temperature in Fahrenheit or Celsius. The 6-foot (185cm) cable length gives you ample room to move your controls closer to where you need them.
The LED display has a display range of 32 – 140F (0 – 60C), while the actual control range is 40 – 108F (5 -42C). Setting the temperature is as easy as holding the SET button down for 3 seconds. Once the display starts flashing, you simply use the UP/DOWN buttons to adjust it. Once you have it dialed in, hit SETA once more to lock it in.
Accuracy
The Mars Hydro seedling heat mat has a pretty precise digital thermostat. It takes its reading from the included remote probe, and using a fast-processing power chip it will accurately display the current temperature and power off immediately after reaching the set temp.
We tested the accuracy of the digital thermostat controller to see how accurate it was. For our test, we placed a plastic tub with a 3-inch layer of cocoa coir on top of the mat and placed this all inside a grow tent. The probe as inserted into the center of the tub, half way into the coco.
After waiting 48 hours for the temperature to stabilize, we checked the temperature with both a calibrated digital thermometer and an IR temperature gun. The results were spot on, with the temperature only off by less than 1 degree F (Mat temp set to 75F, measured temp was 74.6). I think this is definitely accurate enough.
Quality Check
The Mars Hydro Seedling Heat Mat with Digital Thermostat is well built. The control box is perfectly laid out and all the buttons function great. The 6-foot power cord lets you hang the display in an easier to access location.
The mat itself is covered by double water-resistant PVC insulated layers and fitted with over-heating protection that makes operation safe and cleaning convenient. The 2 layers provide both insulation and allow this mat to conform to the IP67 waterproof rating.
The mat brings your seedling trays (or whatever you are warming) to the desired temperature quickly thanks to the IR heating technology. Being an IR mat, its not good for heating a space so it won’t really affect the temperature of your grow tent. It will, however, heat up your trays perfectly.
If you ever have any issues with the mat, Mars Hydro has a large Social Media presence and you can reach them for suggestions or solutions at any time.
Overall Impression
We really like the Mars-Hydro seedling heat mat with digital thermostat. It heats up super-fast and doesn’t waste energy heating up your grow tent. The mat itself doesn’t get as hot as a mat with a heating coil in it, so there is less worry about it burning the bottom of your seedlings.
The controls are well laid out, and the button are easy to push. Setting the temperature takes seconds, and it is dead on accurate. The mat is a bit hard to unroll if it is cold, so I suggest plugging it in and turning it up to the max for about 15-20 minutes. This makes it much more pliable.
We like to use these IR mats to maintain our mushroom grow tents, as they are super accurate in their temperature control. They heat only the substrate and not the surrounding air, so it makes keeping our tents at the perfect temperature very easy.
For seedlings, the large mat (48×20.75in) perfectly fits two standard 1020 trays. It also is a precise fit for the bottom of a 4×2 grow tent, making this the perfect mat to use when growing in a cold location, such as a basement.
If you are looking for the best quality seedling heat mat with a digital thermostat controller, check out the latest offerings from Mars Hydro!
Ive used the mats from mars hydro and they work good for me. I just wish they made a square one. Never tried the vivosun ones but they have a square one so I will probably get one to try.