Blue Cheese, UK Grow

After the problems that I had in the first week, the plant is now growing normally. Is growing way slower than what I was expecting but that may be caused by the growing environment. The temperatures are quite low this time of the year, when the light is turn on the temperature swings between 19-21, when the lights are turned off the temperature swings between 14-17. The humidity swings between 60%-80%. The extractor fan is still turned off because if I turn the extractor fan on, the humidity will drop below 50%. I have the passive air intake open, but I don't think that is enough. I'm waiting one more week for the plant to grow a bit more so I can turn the extractor fan on, and install the oscillating fan. Due to these conditions, the plant did not need water during this week, which is a very bad sign. I'm supposed to give water to the plant at least 2 times a week