1) Worms don't understand how the three tray system is supposed to work. I have tried to explain it to them, but they don't seem to get it. You will always have worms in all three trays. Hopefully, you will have fewer worms in the bottom tray, so harvesting will be easier. Theory and practice aren't quite the same when it comes to worms.

2) I stopped adding sand to my bins, and I haven't noticed any difference.

Mike, your idea will work best if you leave the lid off. That will allow the VC to air dry a bit and the light will drive the worms down.

Did you remember to occasionally make mounds in the lower trays so that the material touches the bottom of the upper tray? That doesn't guarantee totally worm-free trays, but 80-90% of the worms usually will migrate up.

Andrew

Yep, they hang out in their own poop.

When I am ready to harvest a tray, I move it to the very top, take the lid off and put a lamp next to the bin for a day or two. During that day or two, I go out and stir the contents a few times. All the worms will burrow down.

Just the other day I thought I'd check my bottom collection bin of a 4 bin stacked RM. I have a chopstick wedged at the side between the collection and the botton RM bin, sort of like a dipstick to check the oil in your car. The stick is wet to about 1.5". I wedged a paint stir stick on the other side but not all the way to the bottom. These sticks are supposed to provide more air to the collection bin. I did drill holes on the side but doesn't seem to be enough. It used to be quite smelly before I did the sticks trick.
Anyway, there were about 2" wet worm poop and I couldn't believe it: 1 3/4 lbs. of worms. No dead ones or any that I could see. They were all plump and fat and looking healthy.

I use 6 upside down empty cans to support the weight of the worm bins and make it easy to remove. I stopped using shredded paper product for the leachate bin because it made such a mess and hard to separate between the good stuff and the paper stuff. Now I am using corrugated cardboard along the sides and between the cans, folded like a pyramid. A lot easier to remove than shredded.
The poop is pretty wet but I imagine that is 100% castings.

I use the Vermihut system with 5 trays, and I just spent yesterday and today harvesting two trays. I like to start with a spare tray with fresh bedding for the worms to move into. I put this one second from the top, with the tray I want to harvest on the top. My trays tend to get really full, so the trays all sit in full contact with the layers above and below each one. I simply remove the lid and toss the compost a bit to get the worms to move down, away from the light. I do this under the covered porch where they are in the shade. I don't use bright lights or lamps or anything. I have discovered, however, that they will only move about two inches down before they stop, so it works best if I only have about two inches of compost in the bin. My bin had about 5 inches of compacted compost in it. I took most of the compost out of the bin and put it into a bucket (worms and all)and left only two fluffed-up inches in the top tray with the lid off. After a few minutes, they had almost all disappeared into the tray below (to fresh bedding and food). There were a few stragglers, there always are. I took the now worm-free compost to the sieve and then put another two inches from the bucket to give the worms in the second batch time to migrate to the tray below while I sieved out the first batch of compost. It took three batches to de-worm and sieve the entire tray. It worked great because one batch was about all the sieve could handle at a time, anyway.

Two things that slowed me down were:
1) being slow to figure out that the worms would only go down far enough to escape the light, and then stop....they will not exit the tray just because I wanted them to. I learned only after my third attempt that I had to remove all but two inches of compost if I wanted them to exit the tray.

2) Carefully hand-removing the casings from the finished compost. My 7 yo nephew helped me pluck the cocoons from the first batch. It is tedious work, especially because I tend to be a soft touch and don't want to lose any of the little cocoons. By batch three, I just threw the gallon of sieved compost (with bazillions of eggs in it) into the little worm hatchery I've started, and figured I'd get the compost in a few weeks when they've all hatched.

I think in the future I'll follow the advice posted elsewhere in this forum and simply send all sieved (and worm-free) compost to the hatchery instead of spending hours trying to hand-sort the cocoons. I realize that initially this may mean a longer wait before I can use the compost in my garden, but if I harvest regularly, then the hatcheries will start finishing in regularly-timed batches.

I hope that you will find something in my experience that will be helpful to you. Good luck with your worm bin!

I usually just lurk and check for information about once a week. Laughed my head off when I read this ...

"Worms don't understand how the three tray system is supposed to work. I have tried to explain it to them, but they don't seem to get it."

My worms will have to be in remedial school with yours, sbryce. A few days ago I added my second tray and today checked to see if there was movement. There is, but boy are they slow!

Thanks for the chuckle!

Robin in NC

Worms4Tracy: That info about the 2" is great. I've never noticed or thought of that. I'll do it your way for the next bin harvest. Thanks.

Some worms like it down there -- been down so long, it looks like up to them.

I just dump the bottom bin into a regular plastic storage bin in the morning and put it in the sun, and every hour or so take off the top inch or so. Once you're down to the last inch you can just put the whole lot back in the lowest bin.