That's not a method I would personally use.

One thing I am wondering... what's the temperature in the ROOT zone... I think it's more important than air temperature actually.

Plus the placing the pellets IN water... I don't know... yeah, I've seen the instructions to do it how you are but if I were you I would get them out of the water and concentrate on keeping the pellets moist and slightly warmer than air temperature, and the leaves misted (hint: I am now using a fungicide in my mist... just a precaution). A

Also, humidty=50% is not enough. Do you have a dome? Humidity approaching 100% is normal. Again, there are plenty of growers who will tell you no dome just anti-transpirant, but with something like wiltpruf, humidity oviously becomes almost moot... the rate of moisture loss is cut DRASTICALLY.

Hm