If you are using a glass or plastic tank then the heat mat is placed outside the tank.
How to use heat mat without the thermostat.
Temperature is so important in the germination phase so having the thermostat will allow you to more finely control and set safety shutoffs.
Many people suggest that you should use a thermostat to more precisely control the temperature.
For heat mats you can use a on off or mat thermostat.
Since a heat mat can be pricey at 30 50 you want it to grow with you because maybe next year your garden will be twice the size.
The tank is then place on top.
I ve never used a heat mat without a thermostat.
Learn how to use the jump start heat mat and thermostat to effectively control and maintain your seed starts and germination.
How to use a thermometer for seedlings to make sure the mat is accurate we also use an extra thermometer that gets inserted directly into the soil.
I m really not comfortable doing this without a thermostat but obviously i can t go and buy one at 9 30pm.
There is three leads that come off your thermostat one is the plug another is the plug socket for your heat source and lastly there is the probe.
The polystyrene provides insulation directing the heat upwards towards the tank.
Without the use of a thermostat which they do recommend the highest i got was 30c which is plenty for starting seeds.
If heating mats only raise the temperature by 10f 5c then their benefit is much reduced.