@Ciore, thanks for your question. In my case I think that is a heat problem because my country was having a lot of could days (not only during the night time) and I had to put a 600w HPS bulb, today I will put my 250w HPS bulb again because the temperature with the lights off is about 17/18 Celsius. I will try this option and if you want to keep the contact with me to more information.
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