I use a fan when seed starting but turn if off when I turn the light off. I don't have either running 24x7.

FataMorgana

Thanks, Fatamorgana. Do you have the fan on your seedlings after you've transplanted them into pots and they're growing? If it's good to have the fan on after they're potted, I'm trying to figure out how many hours a day to run the fan for.

I use the fan after they have sprouted for air circulation and to encourage stronger, less spindly seedlings. I do use plant lighting but sometimes those seedlings just stretch too tall too fast. After I have done the first transplant into pots, I'm usually hardening off outdoors in a sheltered location so the fan isn't in the picture.

I turn the plant lights on after I get up in the morning and off before bed. Fans, if I'm using them, on the same schedule since they are plugged into the same power strip. Works for me.

FataMorgana