Bruce-

I have always had mine on a few times for a couple of hours each, those hours dependent on a couple of things. I typically liked the fan on when I was home...that's just my cautious self. So a couple of hours in the evening and early morning. Going on in the middle of the night was ok too. The fan didn't affect my heat bed, but that sounds like it might be something you need to work with. Oftentimes I would just kick it on/off when we were either working in the room and were hot or cold:) Certainly no scientific basis to the way we do it, just what makes us feel safe and sound AND gets airflow to our babies:)))

I'm a first-time grower, so take this as input more than advice (as I don't know how this'll turn out) :)

I have a 40W fan that I use whenever I'm at home during the daytime. I work from home 2-3 days a week, and during those days I have those seedlings lightly dancing in the wind for up to 8 hours. Maybe also a couple of hours during the weekend. And that's it. Seedlings are thriving so far, at least they don't seem to be bothered by the wind.

So far the general consensus seems to be longer periods of "wind" on the little fellas. I can program the timer however I want, but I will wait to see if anyone else has any input.
Thanks all,
Bruce

I am using one of those 3 foot oscilating cylinder fans in my laundry room where I have my plants going. No set times but I like the idea (and working so far for me..) when I turn off the light the fan goes on. Light on, fan off and all the babies are thriving right now. I have it on low and about 4 feet away from the seedlings. They "wiggle" and are getting very stocky.

Bill

should I set it for less on/off cycles and have it on longer or more on off cycles and on less or other combination like more cycles and more time on each cycle? Well, I liberally "fanned" inside seedlings (peps and mots) for 1st time in 2012 season. One instance, I realize, is not much a test. Whatever, in that season, I had no noticeable problems with nascent fungal infections. Ran fans(s) on lowest settings for at least 12 hour/day. And moved fans' locations such that air movement was changed about 180ú every few days.
No gale-force winds here... my idea was to get most of the plants to wiggle a bit in the gentle breeze. Yes, that will usually lower the temps of soil if it is being heated. But at that stage, my heating thing is pretty much over and they are growing at ambient temps.

Reggie

I try to turn the fan on for all of my houseplants (and seedlings) at least three hours a day, especially after watering.

I keep mine on 24/7, for all my plants. The reason for this, is that the constant gust of wind helps to strengthen the plants and keeps the air circulating in my grow area.

I grow indoors, so when I designed my growing area I planned for this constant air. The temps are still where I need them to be and it seems to work really well, and avoid spindly plants.

My fan stays on low at all times, when my plants are big enough sometimes I adjust it to a big stronger. I find doing these things not only makes for strong plants, but also when the plant is growing fruit they can support that much more weight versus a plant grown without constant 'wind'.

I know some might argue that it's too much, and that may be.. Although it works for me!

Another good thing about a fan is that it counteracts the "microclimate" at the window sill, if that is where your plants are. Keeps the air at the sill just like the rest of the room. That argues for 24/7 circulation.

OK, great input guys. I think I will go with a longer 2 o 3 hour period maybe three times a day.
Thanks to all that provided input. Great help.
Bruce

Great advice. I started using a fan the other week but have been randomly turning it on and off as I wasn't sure what to do either. Like the timer idea. Does anyone know if tomatoes respond well to the giggling to become beefier?

Hillseeker,

Last year we ran a fan nearly 24/7 on our tomatoes and peppers and had very good luck even in less than optimum conditions.

I haven't started tomatoes just quite yet. I will probably tomorrow however, and will probably start the fan on them as well once they get an inch or two tall much like last year.