I usually cover the actual bedding with a good layer of shredded paper. That paper probably shouldnt be wet but either damp[sprayed with mister] or it can even be on the dry side. I use that layer to mainly keep gnats and fruit flies out.

Also if the bin is mad of plastic like one of mine then leave it cracked so moisture can escape. I accidently locked my lid on the other day and a lot of worms were at the top lip ready to escape. That is the one disadvantage of using a plastic bin. If the bin is too wet they will start to escape.

Short answer: When it's full and looking 80% done. Your mileage may vary but for me I find myself rotating trays monthly.

Long answer: I have been using my Worm Factory for over a year now. I bought 2 extra levels from the original 5 I think. I keep the top level full of shredded paper only... to keep worms lower and reduce fruit flies.

Used to be far more careful about stuff at first but now my cycle is this:

* store veggie scraps in freezer

* prep a new tray once a month with moist coconut coir and shredded paper and add a week's worth of thawed family veggie scrap (4 people, lots of fruits and veggies eaten)

* add new veggie scrap once per week to the new tray, drain spout to cup and pour that into a watering can for garden use

* check the bottom tray and base once per month - clean base and drain it as needed; if bottom tray looks 80% done or better, transfer to plastic container (an empty cat litter container) filling it half full and keep the worms in it; leave plastic bin lid cracked open an inch, worms don't leave; use in garden when ready (I don't make tea, just put this worm-rich mix onto garden surface) - rinse used bin in garden, clean with soapy water and prepare for reuse when needed

* add new veggie scrap once per week

I find that it takes about one month to produce an 80% done tray with this cycle.

There are PLENTY of worms. I have no worries about taking a tray full out of the cycle. Usually the bulk of my worms have moved higher anyway. I'm sure my garden soil is much happier and healthier with its new worm guests as well.

Paul

Not sure I follow you completely although I am also harvesting about once a month with my 360 but Im only using 3 trays. You say with your top tray you only have shredded paper no other food and is that paper dry? Also you say when you prepare a new tray with a bedding and food and shredded paper does that tray then go on top or does it go under the top tray which is full of paper only?

The tray containing nothing but shredded paper stays at the very top at all times underneath the lid. It's there to keep fruit flies down and also keep worms from being on the lid when I remove it so the lid can serve as a worm-free base for the other trays as I inspect them.

Every couple of months I will clean that top paper-only tray and put it to the side, then take one of the previously cleaned trays and put fresh shredded paper in it to make the new top paper-only tray. I do this every couple of months and when I do so I use some or all of the older shredded paper as part of new bedding for the second-from-the-top tray.

The four trays that come with the Worm Factory 360 are enough for casting production and housing but I like having the extra two trays that I bought so that I can have this top paper-only buffer and so that each tray gets a good cleaning every 3 or 4 months.

Paul

Thanks for your return comments and info. The only problem being with the top tray paper only theory is worms will also eat the paper and once your herd gets big enough they will leave no stones unturned and it may take more attention than that every 3 or 4 mo.

You're welcome. They will eat some paper, yes, but I am not seeing it in the top tray. I feed weekly in the second from top tray. That dry, paper-only top tray seems to be an effective barrier for both worms and fruit flies, but I imagine if I turned my back for a month there would be worms in this top tray. - Paul

Just to follow up my top dry paper only does seem to be going down a bit so maybe they are making some use of it as when I take it off I see worms hanging from the bottom and the paper level going down so I just add more as needed. Im thinking Im going to go ahead and add the fourth casting tray or feeding tray. When I ordered My 4 tray system also got a fifth tray so might as well use them all.

It must be cool to see the worms like that.