This is the second summer I have used my Biopod. Last summer I used the Coir mat that came with the unit. Only on one day did I harvest about 12 grubs in the collection bucket. The rest of the summer (and fall) they simply didn't go in. This summer I tried again and used a Coir mat I bought and was still not getting grubs in the bucket. I dumped it out in August and there were a whole bunch under the thick Coir mat and I harvested those which was great.
I decided the Coir Mat was too thick and they were all underneath it and replaced it then with a 1" air filter. I am still not getting any grubs in the collection bucket and I checked under the air filter and there aren't any. There is always tons of grubs in the main unit, they just go into the bucket prematurely and are very tiny and white.
I have talked to Karl several times this summer about this. I bought the Biopod from him and he thinks they aren't getting enough moisture. But I spray them several times a day and it is definitely moist in there. He said it might just be the area of the country I live in as he has heard the same thing in Arizona. I live in Boise, Idaho and I'm wondering if anyone else with a dry climate has had success getting these grubs to migrate into the collection bucket when they are mature. I feed them food and coffee grounds everyday and I can see them all in there working but daily when I check the bucket, just tiny immature ones that I dump back into the main unit.