After a week in the bucket, the ppm it's 310, and there is still water touching the roots/Rockwool. I read in another Growdiary someone was changing the water and putting more nutrients every 10 days, so I will wait for a day or 2 before changing it. I think I need to keep around 400-450ppm, and I don't want to put too much. I turned on a small fan, open the tent a little for some air circulation, and turned on a humidifier. The solution's temperature yesterday was 24.4C (75.9F), the internal temperature is was around 25C (78F), and the humidity around 51%. The PH was 6.
After my first year of growing, exclusively DWC, here's a few tips I've picked up. Water level should be about half to full inch below bottom of cup or wherever the bottom of your rockwool lies (Once true leaves show so roots can grow "down" towards the bottom where water is). Just a small tip. Now, what I learned over the past year, the single most important factor (to avoid root rot): Watch and monitor that water temperature. Keep it clearly under 80 degree F. You do NOT want warm water just sitting in some deep reservoir. I made that mistake, couldn't keep Temps below 80 degrees and struggled to get humidity up past 30 percent. I ended up having to throw out 4 plants a few weeks into flowering. That temp you have of 75-78 is good. Humidity is OK, but if you can try to raise it a little higher at this point, early in Veg, would benefit, but pay more attention to that water temp. PPM should also hit around 900 at end of veg. I usually start veg at about quarter strength or less (1 ml/L for first week). Also the larger your reservoir the less often you should have to change nutrients. A larger ecosystem should set up for a more stable environment as far as numbers go. Good luck with your grow and I'll be following along.