BioPod Log-waste in-grubs out


BioPod spring cleaning

This is a log of everything I will add to and remove from my BioPod this year including BSF grubs harvested. I will give an exact weight and general description of the waste added. The data will include the weekly and monthly ratio that waste is converted into grubs.This begins with a spring cleaning of my BioPod after which I added a small amount of compost and a few hundred BSF grubs from last year’s colony. These grubs were laid in the fall of last year and kept through the winter by insulating the BioPod. Of course the moisture content can vary a lot (dry tea bag/wet tea bag) and this makes a significant difference in the weight, so please use this log as a very general reference.

It will take a few weeks before the first new grubs begin to mature and self harvest. Until then there won’t be much to remove. Once the first generation begins to mature we’ll start to see what kind of ratio of food scraps to grubs I get. Converting food waste into grubs is called bio-conversion and there have been reports of ratios everywhere from 8% to 24% waste/grubs.

I often collect eggs from my BioPod before they can hatch and I use these in starter kits for our BioPod customers. I also harvest juvenile grubs and many times this includes a significant percentage that are very small. I’m not sure how this might effect the conversion ratio but I thought it was worth mentioning.

I will be weighing using the metric system and roughly converting to ounces.

May 3, 2009 waste in = .4kg
  • Sat + 14 oz (.4kg) bread
May 4-10 waste in = 1.4kg
  • Tue + 10 oz (.3kg) coffee grounds
  • Wed + 15 oz (.42kg) banana peels, raw potato, used tea bags
  • Wed + 8 oz (.23kg) wet spoiled fish food
  • Sun + 16 oz (.46kg) fruit, bread, cheese, rice
  • average daily input = 5oz (.14kg)
May 11-17 waste in = 2.9kg grubs out = .04kg conversion rate 1%
  • Thur + 9oz (.25kg) coffee grounds, 18oz (.5kg) bread, banana peel, canned tomato
  • Sat + 10oz (.3kg) corn grits, tea bags (5 large), fruit peels, 2oz (57gm) dry fish pellets
  • Sat – removed 1.4oz (40gm) mature grubs which was .5 cups (115ml). (403 grubs)(yes, I counted them) :)
  • Sun + 7oz (.2kg) bread, rice, fruit, 1 lb 11oz (.78kg) whole fish
  • average daily input = 11oz (.3kg)
May 18-24 waste in = 3.12kg grubs out = .037kg conversion rate 1%
  • Mon + 11oz (.31kg) whole fish, 9oz (.26kg) muffin, fruit, veg
  • Tue + 13oz (.38kg) whole fish
  • Wed + 9oz (.25kg) coffee grounds, muffin, 9oz (.25kg) whole fish
  • Thu + 5oz (.15kg) whole fish
  • Thu – removed 1.3oz (.037kg) mature grubs
  • Fri + 10oz (.28kg) whole fish, 25oz (.7kg) chicken skin, fruit, dog food, seeds
  • Sat + 14oz (.4kg) cornmeal, 5oz (.14kg) fruit peels
  • average daily input = 16oz (.45kg)
May 25-31 waste in = 13.88kg grubs out = .44kg conversion rate 3%
  • Tue + 13oz (.36kg) whole fish & scraps, 15oz (.45kg) apple, cornmeal, coffee
  • Wed + 86oz (2.44kg) cucumber, apple, banana
  • Thu + 2oz (.05kg) whole fish
  • Thu – removed 1oz (.035kg) juvenile grubs
  • Fri + 13 lbs 3oz (6 kg) melon rind and a few figs
  • Fri – removed 8 oz (.22kg) mature grubs
  • Sat + 7.14 lbs (3.24kg) melon rind, 7oz (1.9kg) cornmeal, whole fish
  • Sun + 6oz (.16kg) whole fish
  • Sun – removed 7oz (.19kg) mixed grubs
  • average daily input = 4.375 lbs (2kg)
June 1-7 waste in = 5.82kg grubs out =1.02kg conversion rate 17%
  • Mon + 8oz (.23kg) whole fish
  • Tue + 6oz (.16kg) fish, 15oz (.43kg) coffee, fruit, bread, tea bags
  • Wed + 35oz (.98kg) chicken hearts, beets, chili + 6oz (.17kg) fish
  • Thu + 8oz (.24kg) bread, 6oz (.17kg) fish
  • Fri + 31oz (.88kg) salsa, fruit, bread, coffee, 21oz (.6kg) whole fish
  • Sat + 3oz (.097kg) whole fish, 33oz (.93kg) damp grass seed
  • Sun + 31oz (.89kg) rice, teabags, fruit, 2oz (.044kg) fish
  • Sun – removed 26oz (.749kg) juvenile + 9oz (.268kg) mature grubs
  • average daily input = 1.8 lbs (.83kg)

BSF harvest - mature 6-7-2009 BSF harvest - juvenile 6-7-2009

(click images to enlarge)

The photos above are of the grubs harvested on June 7th. The dark grubs are the final larval stage (prepupae) and these were removed from the collection bucket of the BioPod. The light colored grubs are juveniles and I removed them directly from the food pile using the technique I describe HERE. The brown paste on the juveniles is some of the remaining fish food that I used to attract them when I collected them. Also you can see some juvenile grubs mixed in with the mature ones from the collection bucket. They probably migrated out of the BioPod because it was getting too hot inside. If this happens to you and you would like an easy way to return the juveniles to the colony simply dump all of them back into the unit. Assuming it’s cooler inside the juveniles will probably stay while the mature grubs return to the ramps and back into the collection bucket.

June 8-14 waste in = 10.173kg grubs out =.889kg conversion rate 9%
  • Mon + 25oz (.697kg) whole fish, fish carcass, 56oz (1.574kg) melon
  • Tue + 20oz (.569kg) coffee grnds, bread, cornmeal, 6oz (.158kg) fish
  • Tue – removed 1.4oz (.04kg) juvenile grubs
  • Wed + 86 oz (2.446gk) raw corn kernels
  • Wed – removed 6oz (.176kg) mature grubs – 17oz (488kg) juvenile grubs
  • Thu + 9oz (.255kg) canned pet food, banana peels
  • Fri + 31oz (.884kg) whole fish and scraps
  • Sat + 6oz (.165kg) whole fish, 6oz (.170kg) tea bags, cat food
  • Sun + 77oz (2.189kg) whole watermelon, 38oz (1.066kg) peaches
  • Sun – removed 7oz (.185kg) mature grubs
  • average daily input = 3.2 lb (1.45 kg)
June 15-21 waste in = 3.85 kg grubs out = 1.19kg conversion rate 31%
  • Mon + 5.5 lb (2.5kg) whole watermelon
  • Mon – removed 7oz (.185kg) mature grubs
  • Tues – removed 6oz (.179kg) mature grubs
  • Wed + 35oz (.986kg) whole fish, 13oz (.365kg) coffee, berries
  • Wed – removed 24oz (.669kg) mature grubs
  • Fri – removed 6oz (.16kg) mature grubs
  • average daily input = 1.2 lb (.55kg)
June 22-28 waste in = 4.753kg grubs out = 1.007kg conversion rate 21%
  • Mon – removed 14oz (.399kg) mature grubs
  • Tue + 3.3 lbs (1.514kg) bread, bananas, tea bags
  • Wed – removed 13oz (.361kg) mature grubs
  • Thu + 1.4 lb (.618kg) onion, tea, coffee
  • Thu – removed 2.6oz (.073kg) mature grubs
  • Fri + 14oz (.408kg) dry cornmeal, 6oz (.183kg) whole fish
  • Fri – removed 2oz (.050kg) mature grubs
  • Sat + 17oz (.472kg) coffee, tea, fruit, 4oz (.123kg) whole fish
  • Sat – removed 4oz (.124kg) mature grubs
  • Sun + 3.2 lb (1.435kg) watermelon rind
  • average daily input = 1.2 lb (.55kg)

Month of June: waste in = 29.527kg grubs out = .910kg conversion 14%

June 29-July 5 waste in = 10.42kg grubs out = .945kg conversion 11%
  • Mon + 3.2 lb (1.428kg) cornmeal, cabbage, tea bags, 15oz (.416kg) whole fish
  • Tue + 6.8 lb (3.087kg) watermelon
  • Tues – removed 3oz (.086kg) mature grubs
  • Wed + 6oz (.166kg) whole fish
  • Wed – removed 2oz (.051kg) mature grubs
  • Thu + 2.5 lb (1.153kg) whole fish and scraps
  • Fri + 2.7 lb (1.224kg) whole fish
  • Sat + 7oz (.221kg) fish, 19oz (.545kg) coffee, tea, fruit, veg
  • Sun + 3.9 lbs (1.788kg) watermelon, 10oz (.282kg) coffee, wet cornmeal, 4oz (.112kg) fish
  • Sun – removed 1.2oz (.035kg) mature grubs, 1.7 lbs (.773kg) juvenile grubs
  • average daily input = 3.3 lbs (1.489kg)

It’s been about 9 weeks since I cleaned out my BioPod and restarted the colony using a few hundred BSF grubs from last season. At the beginning of this log I posted a photo of my BioPod as it looked that first day and I thought it would be good to show you what my colony looks like now. Below is a series of photos taken over a span of 5 or 6 hours on July 2nd when I added 2.5 pounds of whole fish and fish trimmings. By the next morning there was nothing left of the fish except for the bones.

BioPod colony 7-2-2009 11am 120px BioPod colony 7-2-2009 11am-plus fish BioPod colony 7-2-2009 1pm BioPod colony 7-2-2009 3pm

(click images to enlarge)

To be fair I need to point out that this is my third season culturing BSF on my property. I’ve built up a very healthy population by protecting thousands of BSF grubs through their larval stage, a period when the vast majority of wild grubs would be eaten. I also live in the southeastern U.S. which is the native range of the black soldier fly. Someone just starting out with BSF might not be able to establish a colony as robust as mine in just a few weeks, especially in an area where BSF are relatively scarce.

A few days after the fish series of photos above I took another series with watermelon. You can see some bones which are all that remain from the over 5 lbs of fish from the previous two days.

BioPod colony 7-5-2009 11.35am with watermelon BioPod colony 7-5-2009 11.45am BioPod colony 7-5-2009 12.10pm BioPod colony 7-5-2009 12.15pm close up

(click images to enlarge)

July 6-12 waste in = 9.526kg grubs out = 4.230kg conversion 44%
  • Mon + 4.3 lbs (1.944kg) whole fish
  • Tue + 14oz (.399kg) whole fish
  • Wed + 1.2 lbs (.551kg) ice cream, tea, fruit, 3 lbs (1.359kg) melon
  • Wed – removed 3.4oz (.097kg) mature grubs
  • Thu + 16oz (.450kg) bread, soup
  • Thu – removed 1oz (.027kg) juvenile grubs
  • Fri + 3.3 lbs (1.489kg) wet cornmeal, 5oz (.140kg) coffee, 9.2oz (.262kg) fish
  • Sat + 4 lbs (1.819kg) melon
  • Sat – removed 16oz (.449) mixed grubs, 8 lbs (3.657kg) juvenile grubs
  • Sun + 2.5 lbs (1.113kg) whole fish
  • average daily input = 3 lbs (1.361kg)

Notice that on Saturday of this week I removed eight pounds of juvenile grubs from the BioPod. That’s a lot of BSF grubs. Removing them lowered the level in the unit by more than two inches. As mentioned previously I used a method for removing the juvenile grubs that you can find HERE. Taking out such a large amount at one time resulted in the very high conversion ratio for this week, but with a much smaller colony going into next week we’ll see a correction in the ratio. This batch of grubs were all light-colored juveniles and ranged in size from almost full grown to only a few millimeters long. If these grubs had all been allowed to reach full size then the volume and weight would have been several times more.

The reason I harvested such a large quantity of juvenile grubs is because I’ll be traveling for over a week. Had I left these grubs to mature there would have been a constant stream of mature grubs dropping into the collection bucket while I was out of town. I could have asked my girlfriend to collect them, but I didn’t want to ask her to weigh each batch as I’ve been doing for this log.

Due to this situation I’ve realized that removing juvenile grubs can be a useful management tool for BSF culturing. With such a robust colony my BioPod was running at full capacity and required more careful and regular attention. By scaling back the size of my BSF colony I was able to lower the intensity level to the point where it could left alone for a few days at a time.

The grubs in the photos below are part of the eight pound harvest. I repeated this process a total of three times.

Juvenile BSF grub collector Juvenile BSF grub collector-baited 4.47pm Juvenile BSF grub collector 4.55pm Juvenile BSF grub collector 5.21pm Juvenile BSF grub collector 5.43pm

(click images to enlarge)

July 13-19 waste in = 3.4kg grubs out = 0kg conversion 0%
  • Mon + 13.3oz (.378kg) fish scraps, 2.5 lbs (1.149kg) squash, cherries
  • Tue + 4oz (.119kg) coffee grounds
  • Thu + 2.2 ibs (.996kg) cornmeal paste
  • Sun + 1.6 lbs (.748kg) cornmeal paste
  • average daily input = 17oz (.484kg)
July 20-26 waste in = 5.56kg grubs out = 1.429kg conversion 26%
  • Tue + 2 lbs (.947kg) cornmeal paste
  • Thu + 2.8oz (.079kg) whole fish
  • Fri + 4 lbs (1.822kg) watermelon rind, 15oz (.414kg) fish
  • Sat + 12.6oz (.356kg) whole fish
  • Sun + 4.3 lbs (1.942kg) cornmeal paste
  • Sun – removed 3.15 lbs (1.429kg) mixed grubs
  • average daily input = 1.75 lbs (.794kg)

Month of July: waste in = 29.527kg grubs out = 7.43kg conversion 25%

July 27- Aug 2 waste in = 6.659kg grubs out = .905kg conversion 14%
  • Mon + 5.1 lbs (2.321kg) melon, 1.4 lbs (.612kg) coffee, bread, snake (killed by dog)
  • Tue – removed 2 lbs (.905kg) juvenile grubs
  • Wed + 14oz (.399kg) pasta Alfredo, whole fish
  • Thu + 2.25 lbs (1.927kg) melon rind, 5oz (.137kg) whole fish
  • Fri + 11oz (.316kg) vegetables and grains
  • Sat + 10.4oz (.295kg) fish, 11.6oz (.329kg) Ortega mild green chili sauce
  • Sun + 11.3oz (.321kg) whole fish
  • average daily input = 2.1 lbs (.951kg)
Aug 3-9 waste in = 7.506kg grubs out = 1.543kg conversion 21%
  • Mon + 1.4 lbs (.616kg) whole fish
  • Tue + 4.6 lbs (2.073kg) melon, rice, coffee, onion, 2.4oz (.069kg) fish
  • Wed + 7oz (.206kg) pears, coffee
  • Thu + 10oz (.290kg) fish
  • Thu – removed 2.8 lbs (1.262kg) juvenile grubs
  • Fri + 1.5 lbs (.690kg) pears
  • Sat + 7.2 lbs (3.254kg) whole watermelon, 10.9oz (.308kg) fish
  • Sun – removed 10oz (.281kg) mixed grubs
  • average daily input = 2.4 lbs (1.07kg)
Aug 10-16 waste in = 2.86kg grubs out = 0kg conversion 0%
  • Thu + 3.74 lbs (1.695kg) watermelon rind
  • Sat + 1.5 lbs (.697kg) fish
  • Sun + 10oz (.279kg) coffee, banana, 7oz (.193kg) fish
  • average daily input = 14.4 oz (.409kg)

close up of adult BSF

I thought it might be a good time for a photo. :) Black soldier flies rarely land on people but this one had just emerged from pupation so I was able to admire it for a few minutes before it flew off in search of a mate.

Aug 17-23 waste in = 10.02kg grubs out = .333kg conversion 3.3%
  • Mon + 5 lbs (2.306kg) melon rind
  • Thu + 3.4 lbs (1.527kg) melon, 7oz (.212kg) coffee grounds
  • Thu – removed 1.5oz (.043kg) mature grubs
  • Fri + 2.8 lbs (1.286kg) melon, 12oz (.345kg) fish, 9oz (.252kg) bread
  • Sat + 9 lbs (4.094kg) Kieffer pears*
  • Sun – removed 10.2oz (.29kg) mature grubs
  • average daily input = 3.16 lbs (1.432kg)

*Kieffer pears are an old hardy variety that doesn’t get soft like most. It’s used for cooking and canning and I’m curious how long it will take the colony to consume them. These pears added a lot of weight to this week’s total which should be balanced out by significantly higher ratios in the near future.

Update: apparently the Keiffer pears aren’t as hard as they seem, at least not to the grubs. :) They were mostly eaten within a few days.

Aug 24-30 waste in = 4.99kg grubs out = .474kg conversion 9%
  • Wed – removed 2.6oz (.075kg) mixed grubs
  • Thu + 5.3 lbs (2.394kg) cooked rice, 2.3 lbs (1.026kg) fish
  • Fri + 8oz (.226kg) coffee, 3 lbs (1.344kg) cornmeal paste
  • Fri – removed 6.6oz (.188kg) mature grubs
  • Sat – removed 7.4oz (.211kg) mixed grubs
  • average daily input = 1.6 lbs (.713kg)
Aug 31-Sept 6 waste in = kg grubs out = kg conversion %
  • Tue + 9.2 lbs (4.154kg) Keiffer pears, 10oz (.285kg) fish
  • Thu – removed 1.5oz (.043kg) mature grubs
  • Fri + 2.5 lbs (1.124kg) Keiffer pears
Update: Since we now have a discussion forum we will be disabling comments here on the blog. Anyone can read the forum, but to join in on the conversation you will need to register. This is an easy and painless process, and it’s necessary to keep spammers from, well, spamming up the place. :)

The forum can be accessed here (forum) and you will see a link for registration in the upper left corner of the forum. The legal language on the registration form is very basic and is what came with the forum software. In short, we won’t share your information, and please don’t be vulgar or break the law. ;)

  •  Posted by at 8:39 am

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