I have searched for the answer but have come across quite a variety of responses. Is there a minimum temperature for the water in DWC? I've seen some sites where people claim they use water as low as 40 degrees F, while others say don't let it get under 62. I keep my house pretty cold in the winter and temps can get down to around 55-58 at night. I've got two plants, each in their own 5 gallon bucket. I have a spare aquarium heater laying around and thought about putting those bucket in a tote...then filling that with a shallow bath that I heat to around 65-66 degrees, basically just so I can be cheap and not buy another heater. How low do you let your temps dip to?
40F, yikes... that's a sure fired way to stunt or all together stop a plant from growing. Get a cheap $4.00 Cooling Heating Peltier Element, a small $5.00 heat sink, and a $8.00 dual relay heater controller and diy your own res cooler / heater for less than $25.00. They work amazingly well, always keeping your res temp right where it needs to be, between 58f and 64f, i run mine at 62f at all times. I know most peps say that the best range is 62f to 68f, but that isn't right, and here's why that is. The best temp to grow cannabis is 72F, a DWC RES is just like a pot of soil where the roots of your plant must live, so if the best temp to grow cannabis is 72F, and the roots of that plant were 2 - 3 feet down in a pot of soil, the real ambient temperature @ the 2 foot mark in soil when the ground temperature is 72f is exactly 64f, and @ 3 feet it is 58f. So that's why I use the 58f to 64f range as a plants roots expect to be living in that temperature range!