VIVOSUN 10"x 20.75" Seedling Heat Mat and Digital Thermostat Combo Set, UL & MET-Certified Warm Hydroponic Heating Pad for Germination, Indoor Gardening, Greenhouse

This is a beautiful piece of equipment! From the moment I opened the package I knew I had a superior product in my hands.. First off, unlike several of the other brands of heat mats for sale on amazon, there was ZERO time delay to wait for the mat to "flatten out". It was indeed rolled into a cylinder for shipping and packing, but it laid out flat immediately upon unrolling it. One review I read here on another heat mat which sounded pretty good otherwise, said that they had to place books on it for two days before being able to use the mat. Not here! Put this awesome thing into use the moment you unbox it.Next, the functionality and quality are superb. At least one review I read here on this product said that they had to connect this product to a separate thermostat, and/or statements to the effect that this has no proper thermostat, only a thermometer. That is categorically incorrect. This not only comes with a genuine thermostat that works very well, it has a heat probe attached that is accurate and highly useful. Allow me to explain.I bought this heat mat for two purposes. First, to germinate/sprout seeds. Secondly, to assist the germinated seeds in quickly coming up from the soil after planting. This product met my needs and fit the bill 100% in both categories.The first step was to germinate the seeds. I used this mat from the absolute get-go. I found, through testing, that I had to set the thermostat temp to about ten degrees above the temp I was hoping to achieve in my actual seed location. However, this varied depending upon the ambient room temperature. Sometimes I only needed to have it set at about 7 or 8 degrees higher than the temp I wanted to achieve. So for example, to achieve 78 degrees at the temp probe location, I might have to set the thermostat anywhere from 85 to 88 degrees.Try this method: Get a clean plastic plate, preferably one with a flat bottom or mostly flat, so that it makes a lot of surface contact with the mat. Do not use a glass plate, it will not conduct heat well. Take two layers of paper towels, or fold one into two layers, and place in the center of the plate as a square (nothing hanging off of the plate, as this will wick moisture away and possibly allow the paper towels to dry out, a major no-no).Then take a good spray bottle with a nice fine mist and fill it with the following liquids: Reverse Osmosis or filtered water, a small amount of liquid silica and/or fulvic acid (liquid silica for plants), a few drops of food grade hydrogen peroxide, and either aloe vera juice or coconut water or both. If adding aloe vera juice or coconut water to the mix, be sure to use only Harmless Harvest brand coconut water, as it is the only one on the market which is unpasteurized and therefore retains all of the medicinal properties in coconut water. One such component is gibberlic acid, a plant hormone which is a potent stimulator of seed germination. You only need to add about 10% coconut water and 5% aloe vera (which also helps a lot with germination) to the water in the spray bottle, and maybe 5 drops of food grade hydrogen peroxide.Spray the paper towel square that you have put onto the plastic plate until it it saturated. Pour off any excess water into the sink. Now take all of the seeds that you wish to sprout, and carefully place them onto the paper towels so they are not touching one another. Be sure to either make a template of which seeds are where, (my preferred method), or you can even write the names of different seeds right onto the paper towel with a pen before you wet it to let you know which seeds are where if you have multiple types of flowers or veggies that you are sprouting.Once you have your seeds sitting on the towel, take a pair of clean tweezers and gently separate any seeds which are touching or overlapping. Finally, place another folded paper towel on top of the seeds and saturate it with the spray bottle.. Be sure to just get it good and uniformly wet and saturated, but with no standing water. When you have both layers of folded, saturated towels on the plate with the seeds sandwiched between them. just lay the temp probe on the top center of the towels and cover the whole thing with another plate. I found it useful to use a slightly smaller and different type of plate for the bottom plate, so that the top plate's edges hang over the bottom plate, kind of like a "roof". The temp probe sensor hanging out from in between the two plates is actually a good thing, as this gap provides air to the seeds and can help to prevent any mold or bacterial issues.For my particular project, I was shooting for 78 degrees in my little "humidity dome/sprouting nursery". As mentioned previously, I had to set the thermostat about 10 degrees above or less that to get the right temp in between the two plates. Again, it depends in part on the ambient room temp and what surface you have placed your heat mat upon. A good rule of thumb for this step is to check the feel of the paper towels a few times a day by removing the top plate and actually touching the towels for a few seconds. If they feel cool to the touch, it is not hot enough. If they feel slightly warm to moderately warm to the touch, you are Golden. If they feel quite warm or bordering on hot, you definitely need to turn the temp down.So if you are shooting for 75 degrees, try setting the thermostat to about 82-85 degrees, wait a few hours, and then perform the "touch test" and then do that periodically during the whole time you have seeds sprouting on the paper towels. Also be sure to mist the towels from time to time with the same awesome spray mixture, but only if they need it. As long as the paper towels are moist/wet and do not dry out, you are in great shape. Another important tip: If you have added Harmless Harvest coconut water to your spray bottle formula, you will want to keep it in the fridge for the duration of the germination process, as it must remain refrigerated once the bottle is opened. The coconut water on the paper towels is consumed by the seeds and is also subject to evaporation, and further, is protected by the food grade hydrogen peroxide in the formula, which keeps everything nice and sanitary, as well as oxygenated.For me, following this process with this mat gave me the best results ever in germinating/sprouting seeds. If you follow the above procedure to the letter, you have every chance of getting a 100% germination rate. Ah, but it doesn't end there! Once seeds are sprouted, it's time to place them in the soil!Once each seed has a tiny sprout coming out (only around 1/8 inch is needed), it's time to plant them. I like to use a pair of clean tweezers and grab the sprouted seeds one at a time and place them onto soil, and then cover with a little more soil and water as usual (with the same awesome water mix you have been using in your spray bottle).As if this heat mat wasn't awesome enough just for it's ability to accelerate, jump start and massively increase your germination ratios, for me it shines just as brightly in getting the sprouted seeds to come up once planted. I had several sprouted seeds, ready to go into soil, and the room I was planting them in was only a little under 70 degrees, even with a plant light running. Warmer soil temps make a HUGE difference in sprouted seeds coming up out of the soil. HUGE. This product makes this step the easiest of all.Simply lay out your mat on the table under your light, place the soil/seedling pots right on the mat (you shouldn't have to be using drip trays at this point, as tiny seeds/seedlings don't need much water, and no water should be running out the bottom of the containers). I like to water the soil a little first, before planting each seed, and then once covered with soil, I water them in fairly well, but I do not soak/saturate the soil. Once you have your planted seeds in containers sitting on the mat under the lights, take the temp probe and push it directly into the soil in one of the pots. Unlike the wet paper towels, which can take an hour or two in between each reading to allow temp to stabilize, soil can take four or five hours to stabilize. But it is a beautiful thing to watch.Since there will be some heat from the lights raising the soil temps in addition to the heat mat raising the soil temps, you will need to adjust for that, and you may need less than ten degrees over the desired soil temp for the thermostat temp setting. On the other hand you may need a few more than ten degrees higher for the set temp than the desired soil temp result. It depends upon what type of lights you are using and how much heat they emit, and how big and how full your soil containers are, as well as how far away from the lights your pots are. Be SURE to monitor the heat mat and keep it far away enough from any lights, and to touch it periodically to ensure it is warm, not hot.You will find, as I did: If you simply place the planted seeds/soil pots under grow lights, they will indeed come up. However, it will be considerably slower and less vigorous. I took five pots this morning that had five germinated seeds in them, and placed them on the heat mat and put the temp probe into the soil in one of the pots. Within about 20 minutes, I could see the soil temp climbing! Within a few hours, it had raised to 72 degrees! Awesome! Within a few more hours, I had two additional plants come up that would have taken an entire day or more to come up without the heat mat! In all my years of starting plants, I have NEVER had this kind of accelerated sprouting, growth, and emergence of seedlings! Not even close!Summary: This heat mat is a complete game changer for sprouting seeds and starting seedlings! With the right methods and some practice you can expect to have near 100% success time after time. Using my version of the "wet paper towel" technique, combined with this wonderful little mat and thermostat/probe, every seed I put through this process germinated within 48 hours, and some of them in as little as 20 hours or less. Wow! I have NEVER had these kinds of results using wet paper towels to germinate seeds. Oh, it's a good method, but without the heat mat underneath the "nursery", you don't have the evaporation which occurs in the little "plate humidity dome". And convection and evaporation also create and encourage air flow, so it's just a gem of an item for creating the perfect environment for bringing seeds to life! Additionally, using it underneath the soil pots once planted (only for 1-3 days, just until the plants come up, if using lights above them), gave me a 100% success rate with seedlings emerging, and I haven't always had 100% success with that, even when using pre-sprouted seeds. With this heat mat, these methods are as close to fool proof as you can get! Is this mat worth $27? Yep! Yes! Uh Huh! That's an Affirmative Amigo!

This seedling heat mat with thermostat has been a staple in my indoor gardening setup for the past three seed-starting seasons, and it’s performed flawlessly. It delivers steady, controlled warmth that helps boost germination rates and keeps seedlings happy—no issues, no hassle.Pros:✅ Consistent Heating – Ideal temp range for seed starting✅ Thermostat Works Great – Simple to set and monitor✅ Durable – Still going strong after multiple seasons✅ UL & MET Certified – Safe for indoor and greenhouse useCons:❌ None so far!Final Thoughts:If you're serious about germination success, this combo set is absolutely worth it. Plug it in, set your temp, and let it do its job—it’s reliable season after season.

Update to my review—I received the new replacement unit today and the new thermostat is working. Amazon and Vivosun quickly resolved my issue and sent a replacement that took only two days to arrive. Thanks to both Companies for taking care of this! I’ve increased my original 3 star review to 5 stars!Testing it out—you set the thermostat to a temperature, I.e. 74 degrees (Fahrenheit) and insert the temperature probe into the soil or growing medium. If the probe is reading less than the desired temperature it will run the heating pad until the medium is heated to the temperature you want it.My new replacement unit shows all this in degrees Fahrenheit, and let’s you program the temperature in Fahrenheit. The first “defective” one only showed it in degrees Celsius and could only be set to temperatures in Celsius before displaying the Fahrenheit Temperature.The new heating pad, like the previous one works, no issues there. Keep I’m mind though it plugs into the thermostat, the thermostat does not set or regulate the temperature of the heating pad. The heating pad will be warmer than the temperature displayed on the thermostat—as the thermostat is only monitoring the temperature of the soil or growing medium. Once it reaches the set temperature it shuts off power to the heating pad.My older review from earlier this week dealing with the defective thermostat:I am in the process of returning the combination seedling heating pad and thermostat because the thermostat doesn’t work. The unit I received did not supply power to the heating pad. I had set up everything as per the instructions and kept an eye on it, noticing that the “heating” light never came on with the pad plugged in. So I took a non contact thermometer and checked the pad temperature—it was room temp and nothing more, then plugged in an outlet tester (in the photos) to check the thermostat plug in for the heating pad and there was nothing. I’m assuming it’s not wired correctly and contacted Vivosun’s support via email. I emailed them Sunday and have not heard anything back yet, so I decided to exchange the item through Amazon—which had a very easy and efficient way of handling the exchange—they are sending me a new one which I hope works correctly and I have to drop the defective one off at my nearest Kohl’s store customer service department to be sent back to Amazon.I’ll have to update this once I get the replacement unit and can better judge the thermostat. The heating pad works very well and I had to manually regulate the temperature to sprout my seeds. It seems very heavy duty for the wattage it works on and should last a few seasons. I know it’s offered separately from the combination set I had ordered.If it had worked right, the thermostat was easy to set to the temperature on and I like how the probe is designed. The only other complaint I had was that you have to set the temperature in Celsius—but it will display the temperature in Fahrenheit. Some conversion work needs to be done if you want to set it at 80 degrees F for tomatoes.Had it worked and controlled the heating pad, had Viviosun contacted me back with their advice on what to do (it’s rumored on Facebook they are not responding to emails possibly because of being located in China and not working due to current events), I would have given this a 5 star review and written how well it works. Hopefully I can post that review once I get a properly working replacement.

Heats up nicely. Only thing is the ends don't heat up as well, so you have to stay mostly in the middle.