Leave Fan on at Night?

am i supposed to leave the fan on at night for my plant?

yes 24/7. keep that air circulating

You don't have to, but it dosen't hurt either, It all depends on your set up

thanks that could be the reason the stem is getting weak

The blowing wind on the plants may strengthen the stem, although you should not be blowing it directly on the plants, but rather reflect it on some kind of wall or obstacle. Fan is mostly used to promote air circulation and to prevent molds, strengthening of stem comes second. I would consider deficiencies or light height rather than lack of wind when speaking about the stem appearing weak.

peace out

also it helps with smell. if u leave them without constant airflow the stink gets thicker