I really appreciate the help GW. I'm toying with the idea of forced air ventilation up through the compost - if it could be maintained in a friable condition. I was going to put pearlite in the bottom of the bin but I like the corn cob idea too. The ventilation would drive off a lot of moisture, but our RH is almost always above 70% and it rains a little almost every day here.
Still thinking about the Velcro thing and a lip on the bin.
I may do without the foreced-air ventilation until another issue can be resolved. We have a small fish farm (ornamentals) which generates a lot of culls. We want to incorporate the culls into the BSF feed and then use the prepupae to condition broodstock for spawning. We have a very thight biosecurity program and I understand your concerns about using animal product in the bin and then feeding the prepupae back to the same species. In normal vermiculture composting this would be a definite no-no. You may be able to get away with it using BSF though because they cast off the gut lining in the last molt and it is unlikely that fish viruses are incorporated into insect tissue. So, you would only have to worry about contamination on the outside of the prepupa and there are various way to disinfect them externally. It's going to require an expensive lab test to confirm it, but I'm pretty sure it will turn out OK.
