Effects of Temp Swings?

Same here in my shed -- down to 64 at night with just the small space heater, ~80 when the 600W HPS comes on. This time of year heat is the lacking commodity, so instead of exhausting the air-cooled light air out the shed, it just recirculates. I am moving air, yes, but I'm not exchanging the air...at least, not all that much.

After a few grows, I don't know, it looks like the plants don't seem to mind the temp swings all that much. Perhaps a perfect 77 would do better but for the time being I think my growth is OK and yields are roughly .7g/watt.

I try to turn the space heater down during the day when the light is on, and back up for the night. If I remember to do it. I am not willing to run 12 hours of light at night and 12 dark during the day (in an attempt to better manage temperature swings) because my schedule doesn't allow me to tend to the plants at midnight, nor do I want to work with a green LED headlamp.

All this to say that I don't think you have to worry too much. My plants grow well with a nearly 20 degree swing. This is my current grow, shot this morning, nine 707 Headband Clones, 28 days veg and now into their 7th day in bloom. This is what 20 degrees of temperature shifting gets me!

 

Oh yeah, you can see in the bottom left, the CO2 airlock from the Belgian Triple that's fermenting. I have no way to measure CO2, but as I'm not venting out/exchanging the air, just recirculating it, this small bit of supplementation stays inside...so I'd wager my plants can tolerate another 1, maybe 2 degrees on the high side.

Play on.

 

Brian, you seriously need to break down that grow op, and I mean now. First off, you won't get help here at GC on how to grow in your parents' house without their explicit knowledge and consent because you shouldn't do it -- it is disrespectful to them, you could get them in serious trouble, and you almost certainly will get caught.

But on top of that your are running a space heater inside a box in the attic? You are risking burning their house down, that's a fire hazard and you absolutely should stop it this instant. It gets worse -- if you do burn down your parents' house there is a good chance their insurance won't cover it because the cause was an illegal grow, which the fire marshall will easily figure out.

Attic grows are notoriously difficult because of temp issues. It can be done, but not the way you are going about it.

In order to grow you need more than a desire to do it, you also need your own secure place and a proper setup. If you don't have that then you need to wait until you do.

 

I hadn't considered that side of it...your argument makes perfect sense.