Soil Temperature to low ?

I just measured with my meat Thermometer and the soil is in the core 19.5c

BioBizz says the temperature should be between 22° and 28° if i remember correctly. So the microbial activity in the soil is working like it should and the plants get what they need. It seems to be normal when growing organic, same for me with Biotabs. Sadly i can't get it above 20° and so far it's still working ok, so if you don't notice problems i wouldn't worry about it, but if you do this could be the cause of the problem. I can speak just for myself, but im not gonna invest 50 Watts+ with current power prices just to get the soil temperature up. Also if i get it up, the temperature in the tent will rise also and people always say that in flowering you want to stay under 26°, how should i do that if i heat my floor/tent up to get the soil temp up, this is impossible. Because of this i let my light run at nights, so i get optimal air temp at night and the soil temp will not drop below 19-20° over the day when the light is off. can't do better then that.

Pues opino que tus plantas no se van a alimentar debidamente ya que el soil esta por debajo de los 21-22ºC lo suyo es que calientes un poco el agua antes de regar