• First, be sure your larva bins are shaded - don't add extra heat to them by the sun heating up their bins (besides, the larva hate the sun light).
• One things I've done in my traveling system is empty my automatic ice maker bin into the tank daily. So, if you have freezer space, you might fill up a bucket or multiple containers with water, then each day drop them in the reservoir.
• If in a green house, and it has walls, consider removing the end walls since NO fan will ever be able to remove enough heat.
• One idea I've had (not tried) is if possible, bury (like 2' deep) a big roll of the landscape type black tubing (larger diameter than your pump uses) in a big coil with at least 12" between bands. Then when in the hot season, have your pump routed through the coil, which will cool the water. Similarly, in the winter in colder areas, this could be used to warm the water. You would need a larger volume pump if you do this since 100' of tubing causes some friction (using the larger diameter tube helps).
• Along those same lines, you could just try burying your water tank to 1/2 it's height or more (I doubt burying any less will matter). And as well, this may help for colder climates.

• If you have a green house with a exhaust fan - turn it off. It can get up to 120 degrees in the green house, and that is OK when it drops in temp overnight. Ideally, you want no lower that 50 degrees at night.
• See the second to last and last item above in the too hot section.
• I use a ceramic reptile heater with a thermostat control, so I stick the sensor into the BSF compost where they are active, that way the heater does not come on unless they are not creating enough heat themselves. You could use a filament type 100 watt light bulb, but the larva don't like light, so that would be sort of punishing them. Adding a heater in this way will at least get them through cold nights. The larva will die if they actually get to 50 or below (or in that range). As well, if they are cold, they are going to go dormant (stop eating), which gets you nowhere.

Problems & Solutions

• STINKY compost- means that it's gone anaerobic (no oxygen) and has "bad" bacteria. The compost should almost always smell earthy, and never stinky. If it is very wet, then you don't have enough drainage (did you add 1.5" of crushed egg shells first?). Or if your compost is very deep (more than 4") it may compact and not get enough air to the bottom. If you add a bunch of anaerobic compost to the reservoir, you may kill any fish if you have added them.
  Solution
  • If you did not add the egg shells, go directly to jail, do not pass GO. Remove all the compost, rinse the bottom screen, add 1.5" of crushed egg shells (that's allot of eggs), then put the compost back AND do the following items also.
  • If stinky like sewage, you need to turn over the compost in the bin well each day to add oxygen and be sure that it can drain until it's no longer stinky.
  • If stinky like rotting food, it is possible to overload your BSF with food, so build up your colony slowly, and only provide enough food that they can process it in 2 days.
• No BSF eggs or eggs not hatching (egg clutch remains for more than a week) - The eggs will usually hatch in 2-5 days, and if they do not, then there is maybe a problem.
  Solutions
  • No enough moisture - be sure to use a lid on your BSF compost bin to hold in moisture, but still allows BSF flies to come and go. Some research has indicated 85% humidity is ideal. Also see notes above about adding a water line to the bins.
  • Not warm enough - The eggs like to be around 80 degrees F to hatch. Cooler evenings are OK, but if the eggs aren't able to warm up, they won't hatch.
  • It is possible they just weren't fertilized. So if most of the egg clutches are hatching, don't worry about a few that don't.

Research on Black Soldier Flies

• In the trays, don't grow plants with lots of roots near the fill/drain ebb/flow fitting (the short one on the bottom). Roots will eventually grow into it and plug it up. I usually plant things like carrots, beets and onions around the inlet side. And so I put really "rooty" plants around my overflow tower where they cannot cause any issues. I also have made some surrounds from thin wall 3" diameter PVC (schedule 20). These allow me to see the roots growing into the drains, then easily just pull them out by hand. I used a circular saw to cut the slots in the pipe for maximum/easy water flow while easily keeping out the growing medium (if you use the expanded clay type).
• When you harvest, try to remove all the roots you can. Leaving behind root is not helping and will eventually lead to plugging up of the hyDroton with organic matter (basically dirt). I will usually uproot the entire plant, then gently shake out some of the hyDrotron (so as to not loose them outside the trays), then clip off the top of the plant, and leave the roots lying on top of the hyDroton for a few days so that the earthworms will migrate out of them back into the trays. After this, work the roots well with your hands to remove all the hyDroton. I usually then rinse the roots in the nutrient solution before discarding since they are usually well coated with dried solution. BSF will not eat plant roots, so don't put them in the BSF bin.
• Start vining plants either against the tray wall by the lattice, or against the wall by a vertical roof support. Tie up the plants to either as they are growing.
• Do not use water hose water (city water) to refill the system. If you do need to use city water, you will need some aquarium dechlorinator since most cities now use chloramines - which will NOT evaporate if you just let it air out like chlorine gas would.Ideally, you would use rain water, well water, etc. If you do use well water, make sure there is not a chlorination system on it, and that it does not have high concentrations of minerals. This is because as the water evaporates, it will leave behind the minerals, which will eventually build up. So if you have high sulphur well water, eventually it will poison your system. I personally use city water with the dechlorinator in it, or reverse osmosis water (use the reject water from RO to water your dirt bound plants/trees).
• Most seeds will start just fine directly in the trays, but try not to place them very deep, like no more than two hyDroton pebbles deep, but enough so they will be wet when the tray fills. Once sprouted, most are easy to transplant and divide to disperse better. Wait until they are big enough that you don't damage them, but small enough that they don't have significant roots yet. When you do transplant, while the tray is full of water, bring your hand in from the side, and come up from underneath, allowing the hyDroton to roll away.
• Don't plant things like carrots and beets right in a dense root area like near the base of a established tomato plant. The dense roots will hang onto the hyDroton pebbles, and prevent carrots and beets from being able to easily move them as they get bigger.
• Do not put raw eggs in your system. I'm not sure why, but it killed all the guppies when I did this. The amount of raw egg on egg shells is OK. Note however that it is *important* to use egg shells in the bottom before adding any food (like 1.5" deep) since they facilitate drainage of the liquidized food, and prevent the bottom screen from plugging up.
• BSF systems have generally be developed to harvest the larva for fish or chicken feed, and you can still do this in the BSF Hydro type system, just be sure that you are seeing enough egg clutches and hatching to support your desired food processing colony size.
• The earthworms are optional. I grew everything fine before introducing earthworms, and after introducing them my seeds seem less likely to germinate in the trays. Dr. N. Arancon at the University of Hawaii has research that shows that earthworms can harvest and relocate seeds, but I'm not sure if this is the case here. I definitely had no problems starting seeds directly before the earthworms, but that is correlation not causation. You can of course start your seeds elsewhere, and then transplant them into the trays. I have not experienced any shock or seedling death as long as careful to inflict the least damage possible when transplanting.
• I have experienced occasional drops in nitrogen levels by watching the intensity of the green color in the cucumber leaves. When this occurs, I've simply added about 2 cups of composted chicken manure (which is very high in nitrates) directly to the nutrient water 100 gallon reservoir. This has not caused any issue with the guppies. I also have found rhizobia on the roots of plants in the system (a symbiotic bacteria that creates root nodules that provides plants with nitrogen). Also, if you have any fresh fish or fish cleaning waste (heads, remaining fillet bodies, etc), the larva love these things and they also will help kick up the nitrate level.

• Simplified timer - DONE. I've located a timer available on ebay for about $8. I generally coat the entire circuit card in silicone or e-6000 to make it weatherproof.
• Cold weather BSF life cycle system - I've built a system at 9,000 ft above sea level in Colorado, and was able to get BSF to pupate into flies. I was unsuccessful in mating and egg laying in what was a brief test in a non-captive environment, and it was not likely ever 80 degrees. I would need to build a enclosed, insulated BSF hatchery which could be kept in a garage or similar space, and use some heat source and artificial light. Ideally this system will incorporate bins mounted over water, with a switched pump for rinsing as needed over the winter. Once it warms up enough inside the hydroponics enclosure, this nutrient concentrated water would be added to the system, as well regularly during the growing season.
• With and with-out earthworms - I like the earthworms in the system, but since the seeds sprouted significantly better in my system before the earthworms, I'd like to make a determination if the two are related, and if so, how they are related.
• How small can it get - I'd like to work on a apartment patio sized system (likely south facing only) and see how well it could work. With only an individuals food waste, I was able to have 27 square feet of growing space filled and producing, perhaps there could be 2 levels of trays along the railing with less sqft, but more concentrating growing...
• Restaurant - I'd like to work with a restaurant who likely already uses a garden for some of their stocks, and solve both a waste disposal problem, and provide fresh vegetables and herbs at the same time. If they already use soil farming, this would also be a incredibly significant labor savings.
• Indoor system - likely this would be similar to the cold weather system, where the BSF bins are in a alternate location, with the trays located indoors along south facing windows. The solution doesn't really have an odor to it, so I think this is a viable situation.
• Top of high rise housing building. Residents could recycle their food on the roof.
• ... and others, but this is the big ticket items I'd like to work on.