In my opinion, I don't think vents or air add much to the process. I have both vented and non vented bins and I like the closed system bins more to protect from flies coming to lay eggs. I do like a bottom that drains to the soil and helps worms to freely come if they wish. I don't like to imprison my worms.

If you have a lot of fresh stuff near the top, I would not open the top. If the stuff is mostly decayed already and you are past the hot stage, there is harm in leaving the top open. I found flies will not lay eggs in my compost once it is a bit more aged. At the later stage you could even transfer to a wire type of bin for maximum ventilation if you have one handy.

The need for air only comes after the compost is past the hot stage. I do think air helps, but not at the beginning. And for cold composting, such as mostly leaves and twigs, the more turning the better and the more air the better.

In aerobic composting, air is everything (especially during the thermophilic phase). Leaving the door open is not a bad idea unless it is going to rain. Keep in mind more air flow will increase drying so moisture monitoring becomes more important.

Lloyd

Thank you so much for your replies. I do have an in-ground large compost pile but have never been able to get it to generate the heat that I have in this tumbler. But I do respect my worms.

The door should be closed, unless the core temp. is 160F or higher.

If you don't mind me asking Robert, what do you base that suggestion on?

Lloyd