Water temps and PPM questions in DWC grow


420 Member
Im starting my first grow in both Coco and DWC
Due to my research water temp should be kept around 20C, 60-65F
I live in an area now temp around 5-15C, 41-59F
So the water will get really cold during the dark I suppose?
it's that gonna be a problem?

Another question
According to my FoxFarm hydro nutrient feeding schedule
The recommend ppm for seeding is 490-630.
but i also learn that not to use any nutrient during seeding from research
Should I use any?
Also any tips for first DWC grow?

Sorry for the poor english, not a native speaker
Don't let your nighttime temps drop below 61 or you will have several issues

Can you explain more?
I use to live in CA, where temperature during the winter is also 41-60F
I've never seem a grower using a heater
instead they need a water chiller
I'm confused
I'm growing in coco, and have a space heater in my grow tent. It was originally set to 65°F.

If you have large temperature drop in your grow area, and insufficient ventilation, you'll run into humidity problems. The water carrying capacity of air doubles with each 10°C or 18°F rise in temperature. This means that if your nighttime temperature drops to 60°F from a daytime high of 78°F and an RH of 50%, the nighttime RH could easily rise to 100%. Good ventilation, and a little heat, say 5°F, will help with this as well.

Other options to control temperature include placing insulation under the tent, and between it and the outside wall. I had condensation on the inside of my grow tent, and corrected it by adding the insulation, increasing the minimum temperature to 70°F, and increasing the airflow. The nighttime temp now never drops below 70°F and the RH never increases above 64%. That's still a little high in flower, but much better than the 85% RH I was reaching on the coldest nights.

You can see the heater in the lower right of this image:


Day 67 of the Grow / Day 42 of Veg

The tent is 2' X 4' X 5'.
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