AC Infinity SUNCORE A7, Waterproof Seedling Heat Mat 48" x 20.75"

Living in Michigan, growing indoor during the cold winter months can be a challenge, especially if you use LED lights and are growing in an area that's not well-heated (i.e. an unfinished basement). I bought these to help increase the temperature of the root zone for mature plants in five-gallon fabric Smart Pots, as well as raise the temperature in the tent overall, since an oil heater in the room outside the tent wasn't quite cutting it. Having purchased an AC Infinity fan, I figured I'd give these a go, as the quality seemed to be good, the price was competitive (not the absolute cheapest, but not the most expensive) and the product descriptions were the most detailed. These mats hold a consistent temperature of right around 90-95 degrees Fahrenheit, but there does seem to be a slight bit of variation between the two mats I purchased (not enough to matter, for my purposes). I found that I needed to use two thin plastic saucers (the cheapest kind available) instead of one saucer, as that extra couple of millimeters of space between the mats and the pots keeps the soil from getting too hot. So, make sure to measure the temperatures of your root zone and adjust spacing between the mats and the pots accordingly, depending on the plants you're growing and the type of pots and saucers you use. I also put two-inch foam insulation board underneath the grow tent, and this also seems to be helping keep temperatures warmer and steadier. Measuring the soil temperature with a probe, I get a reading in the mid-70's, which is about a 15 degree increase from the temperatures I was getting without these mats—exactly as advertised. If your soil is getting too cold for ideal growth, I'd definitely recommend these—especially combined with some foam board insulation to decouple them from the floor. The only thing I wish these mats had are temperature controls (ideally with WiFi control) so you can dial up and down the temperature, as needed. Yes, controllers can be purchased separately, but still... it'd be nice. But for the price, they're great, and do exactly as advertised.

Short version: On Friday evening, I planted some Roma tomatoes. On Monday morning, ~60 hours later, I had visible stems. That's insane. Longer version: Plug and play, no thermostat. Takes many hours to get to the operating temp, be patient. As with all of the heat mats I've used, there's a border around the edge with no heating elements, so the usable area is less than the total area. Cat loves laying on it.

Gets warm fast , shes a big mat

I bought these in May of 2022 to help move along some pepper starts that just were not having much luck in my 70F basement seedling start station area. Without insulation or building a box for the seedling starts, this raised up the soil temps in both seedling start (1.5") trays and 4" starter pots from an average of 63-65F to about 80-82F. Paired with a BN-Link controller that allows me to fine tune the exact soil temp, I'm getting consistent 81.5F soil temps (cross-checked with digital thermometers and two Kinsa medical thermometers used during COVID-19). The caveats here are that in some of the mats I purchased, there is a dial that allows you to increase or decrease overall heat for the mat, and that's useful only if you aren't using a soil temp probe to get exact heat temps. The cords are long enough that I can use them. You CAN place steel or aluminum trays over these to provide a cleaner surface; I don't recommend it, because the additional thermal mass will take longer to heat up and more heat will be lost in an open system. I -highly- recommend using these on a flat wooden surface. If, like I do, you repurpose metal storage racks with grid shelving, you will want to add a flat piece of metal or water-resistant plywood for these to sit on rather than allow them to drape on the grid. They work better at reflecting and retaining heat with plywood than metal. I worried a bit about electric shorts, but realized that the wood simply won't get that hot, and if there is an issue, my GFCI surge protectors plugged into the power strip will handle it long before it becomes an issue. I have yet to try these in an insulated box, cabinet, or tent; my guess is that my soil temps could easily rise. Water hasn't been an issue at all. The mats wipe off instantly and even when a small pool has sat for a few days, it hasn't been a problem. Cleaning them? Just regular spray cleaner and water wipedown. I also used two of these in outdoor greenhouse/leantos during the spring and summer of 2022 as additional heat for pepper plants and tomatoes. They kept temps at the right heat levels to make it possible to grow habaneros and Ajio Limon in the fickle Seattle temp variations. Things that could be better: The cords are sufficiently long to use but it would make me much happier to have the cords start at the corner of the mat rather than the middle of one of the ends. They tend to curl up at the ends if they're unplugged for some time. Part of that is just the natural shrinkage of plastic and metal when it's colder; still, the design could be improved a little. All in all, a solid heating mat for the price and size. If it survives six years or more, I will count these well worth the money.

I had multiple 1020 trays of seedlings going this winter that I have just finished transplanting into the spring garden. This heat mat is the right side to do up to four 1020 trays if you really push the capacity. I would never use this heat mat or any of the heat mats on Amazon for sale without any form of temperature controller, mine being a greater top end industrial process controller known as a PID controller. With the PID controller running the show I had nothing but success with every single seedling I grew over winter. I would recommend again in a heartbeat provided you have a good temperature controller to turn these heat mats on and off. This is the best size for anyone serious. I have the smaller SUNCORE heat mat when I tested heat mats for the first time and would not recommend anything smaller than this for serious gardeners or those growing their own vegetables seriously but multiple of this A7 size so you can get as many 1020 trays on the go as you can ready for the warmth of spring to plant out.

This did not come with a temperature control, however it seems to be self regulating and we keep it on day/night and plan to continue keeping it on in these beginning stages. It gets slightly warmed and seems to be the perfect temp for these little seeds! We planted seeds on Sunday and MULTIPLE plants are (all kinds of sprouts-- green beans, snow peas, mustard greens, cucumbers) already sprouting on Wednesday of the same week. So 3 days to start seeing sprouts. Last year we did not have these mats and it took WEEKS to see any sort of sprouting, we actually thought we had done something wrong. These mats are amazing, highly recommend!

You can almost always count on A.C. Infinity being of superior quality! Everything from them is jave is top notch.

I have larger heat mats but didn’t feel like starting many seedlings this year. This fits perfectly over my kitchen sink and I mounted the control on the wall next to the window. Really like the feature that allows you to adjust the heat level. Well worth the money.

Lovely and large! A must-have for seedling starting.

Good quality flexible and strong material ! We recommand

Heating elements are at least 6" shorter than the mat. Only the middle section is warm.

Well built product. Not so great heat output even on high settings.

Works but wish it got a bit hotter.