Blackberry (Auto) - Fast Budz

The plants have started to sprout leaves and were transplanted from the paper towel/plate to their net pots in the reservoir. It has been extremely cold so the temperatures have been low. Also, the grow space has had high humidity and this is condensing on the walls --> going to have to turn the exhaust on even though they are small. I will start feeding the plants next week as I've read that most seeds can last two weeks without any nutrient supplementation. One of the plants is starting to yellow the leaves a bit though -> deficiency already?