Overnight temp

From what I've read its good to have cooler temps at night, but how cold depends on the strain IMO. I've been told indica's like colder temps and sativa's like warmer but everything is so interbred I don't know if that really matters anymore unless your dealing with landrace strains. I prefer colder night time temps as it mimics natures natural flow in any environment. I prop my balcony door to let in some of the crisp cold air into the room where the tent is. With this i get down to 15-18 at night and average 26 during the day. But before this tent and all the tools I have now, I was always 26c 24/7 for the entire grow and my plants were fine.

Well even if you don’t do anything to make temps drop. Temps drop because the light is off. In flower I’m just at around 25 degrees celsius with lights on and at night I’m around 22 degrees celsius because that’s my household ambient temperature. I’m also in winter here so I suppose you may have a different climate. I wouldn’t worry too much about making it a hard 18 degrees celsius at night, unless there’s a benefit to pushing lower temps at night that I’m not aware of. But I don’t air condition my grow space and I’m pulling 100 grams per plant in 5 gallon pots. But if you want to push 18 degrees at night. That’s completely acceptable for continued plant growth. Hope that answers your question. 🤙