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Tracking Inputs (And Eventually, output)

My wife and I finally did something we haven't wanted to do for years. We bought a bathroom scale. Now as with many things I advocate at home, I had ulterior motives for wanting a scale. Worm related ulterior motives. Sure we could both stand to lose a few pounds, and sure tracking your weight isn't a bad idea, provided you don't become obsessed. But I also wanted to do something our 5 lb kitchen scale couldn't. I wanted to see exactly how much food I was giving the worms, how many coffee grounds were getting dumped in, how much bedding was being used, and in what time frame. 

I've recently become slightly obsessed with the notion of diverting organic materials from the waste stream. Particularly in cases where the 'waste stream' meant dumping it in a landfill rather than taking it away for composting or recycling. Portland, Oregon has an excellent setup, so diverting waste from our own house was still good policy, but not quite as pressing as other places in the state and nation. In Portland, we only have weekly pick up for yard debris/compost and Recycling. Our trash pickup was recently switched to every other week, and the trash can provided only holds max 2.5 bags of trash. Since my wife and I live alone with no kids and no pets, this isn't only doable, we're having fun discovering just how LITTLE trash we can generate. 

So after giving it some thought, talking to fellow vermicomposter Steve Lambert, and watching an excellent documentary related to sustainable building/living called Garbage Warrior, (available in its entirety here []) here were the rough goals I'd set up for myself for the next 9 months.

1: Divert as much organic material and waste from our house as we can. (Within reason... I'm not buying an $800 chipper/shredder just so I can more easily process yard debris that's destined for composting anyway...)

2: Reduce our monthly trash output to 1.5 bags of trash or less.

3: Divert as much waste as possible from work without annoying coworkers. (Primarily coffee grounds and corrugated cardboard for now.)

4: Find a secondary source for coffee grounds/organic waste that doesn't necessitate driving more than 1/4 mile out of my way on a daily basis. (Turns out a Starbucks near work on the border of Portland doesn't have composting, so I can grab grounds daily on the way home which would otherwise end up in a landfill. Usually 25-30 lbs per bag, and only 300 yards outside my normal commute.)

5a: Generate enough compost and vermicompost to revitalize a 50' x 10' space in the yard that's currently clay, gravel, and construction debris.

5b: Generate sufficient compost/vermicompost for the garden so that additional fertilizer isn't necessary. (Possible exception: bone meal)

6: Grow as much food as possible on site. (We live on a rented 4,000 square foot lot with less than 500 square feet of full sun, so we're somewhat limited.) End goal: To reduce our food costs and potentially provide all the produce we need during the spring, summer and fall.

7: Keep a log of all diverted waste (excepting yard debris, which will be too difficult to weigh) and all inputs being fed to the worms. 

So here's what I've got so far. [That's a Dropbox link: it will download a spreadsheet in .xlsx format, and it should be up to date as I use that copy across multiple computers/phone so I can edit on the fly.]  Obviously there are some inconsistencies (water content of coffee grounds for instance) but it's mostly for my own edification anyway. This gives me a MUCH better sense of how much food my worms can process on a day to day basis. For the moment, I have a single worm bin, a 45 gallon VB24 from Bentley's design. If at some point I build another (and I hope to) I'll add lines to track each bin separately. 

ETA: One quick addition for the 3/1 to 3/8 dates: I fed the worms an extra 7.5 lbs (2.5 lbs coffee grounds, 5 lbs food, small carbon addition.) of food last night a few days earlier than I otherwise would have.  I won't be able to do any heavy lifting for the next 7-10 days, and I don't want to have to ask others to feed the worms, so I top loaded the system since it's a flow through and they have PLENTY of space to retreat to if conditions take a turn. I don't expect them to, this isn't the first time I've slightly overloaded this system. They seem to handle it just fine.

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Comment by Steve Lambert on March 8, 2013 at 3:21pm

Dang Ben, you are ambitious!

Don't know if you already intend, or prefer, to do this but you could start sheet composting that garden spot with thin layers of leaves and UCG and by the time the soil is warm for Summer crops you could just scratch it all in before planting.  For Spring planting areas you could sheet compost and scratch, turn, mix it in now and in a few weeks it will be decomposing below the surface, luring the indigenous soil dwelling worms to help out.

I know you're a smart guy and have your situation figured out, but if you need anything I got your back.  Just say the word.  Loading up your worm bin with a little more food than normal can have surprisingly positive results, and it sounds like your bin can handle it just fine.  It's also a good excuse to have to check on the bin conditions on a daily basis to make sure problems don't get out of hand.

Good luck sir!  It will be cool to watch your progress over the next year as you guys realize these guys.  I'll wager a bet that you guys have to give away some of the produce that will burst from your garden.

Nice chart BTW.


Comment by Farrel Stauffer on April 1, 2013 at 5:36am

Great idea Ben!

I am looking forward to seeing your progress. The reason my wife and I started vermicomposting was to benefit our vegetable and flower gardens so I am very interested in your yard reclamation. I also appreciate your "measured" approach to the process.  It will help me as I get started with my VB24 soon.  I was a little skeptical about that bin being able to handle the veggie waste we generate but your early input weights are an encouragement.  Did you start your VB24 with a full compliment of worms, e.g. 4-6 lbs.?  Thanks for sharing your experience!


Comment by Ben on April 1, 2013 at 1:46pm

Hey Farrel,

Here's the tally for this month. Things went well, and I'm averaging about 10-12 lbs/week of food waste, plus bedding materials. 

In lbs:

BIN #1: VB24 (45 Gallon), Insulated, Outdoor.
Food Scraps 44.55
Coffee Grounds 17.05
Carbon Materials (dry) 2.7
Compost 0.25
Leaves 3.85
Total Worm Bin  68.4

And in Kg:

BIN #1: VB24 (45 Gallon), Insulated, Outdoor. -
Food Scraps 20.2
Coffee Grounds 7.7
Carbon Materials (dry) 1.2
Compost 0.1
Leaves 1.7
Total Worm Bin  31.0

I originally stocked the bin with ~3-3.5 lbs of worms, but they've multiplied substantially since November. I don't know how many are in there, but I'm guessing 4-6 lbs at a minimum. Hard to say, I haven't made it a habit to weigh worms, so I'm not really sure what  2, 3, 4, etc lbs actually looks like. 

It's worth noting I did run into some heating issues this month. I had a minor medical procedure 3/8, so I chose to front load the system on 3/7 with a single 14 lb feeding, which is FAR more than I normally feed at once. As a result, the bin heated up substantially and the worms dove/climbed for cover. I don't know how many that might have killed, but the population didn't show any visible signs of a die off. No dead worms, no smell, and not too many escaping. It seems that the VB24 is fairly forgiving because there is a lot of areas for them to retreat to if things take a turn. That said, I'm guessing the very small juveniles probably can't escape quickly enough, and the heating tends to create anaerobic pockets as the microbes use up all the available oxygen faster than air can circulate through. (Or that's the best explanation I've read as to why heating is so dangerous in worm bins.)

Then again three days ago, I had the same issue after I removed the heating cable now that Portland nighttime temps are higher. It was getting snagged on the bottom flow through, so I decided to dig it out, which introduced a lot of air and prompted the microbes to kick into overdrive. 3 hours after I did that, the middle of the bin was up to 100° F. The worms started huddling near the top on the wall, so I removed the leaves I had on top for insulation, shaped the top so it had hills and valleys (to promote additional air flow for cooling) and left the top of the bin ajar overnight. Within 24 hours it had stabilized in the 80s and the worms were happily back in the bin. Again, no visible signs of a die off, but it can be hard to tell sometimes. 

I bring these mistakes up for two reasons... First, it makes me think I may be close to maxing out the food input for a bin this size, or at least for my current population of worms. I suspect more worms or pre-composted food would allow me to increase the amount of weight I feed them. Secondly, if you do want to run a VB24 with a lot of  inputs, your number one concern will likely be heat. It heats up fast, particularly after the first day or two the food is in there. I "age" the food for at least 3-4 days, sometimes as long as a week. That definitely speeds up how quickly the worms move into the new food, but it doesn't seem to prevent heating at all. 

For what it's worth, I didn't track food I put in the VB24 from November to February as I was getting the system established and learning what it could handle. After a couple String of Pearls disasters in rubbermaids, I was hugely paranoid about overfeeding, even though it's not clear if that's what causes SoP. I suspect the VB24 was being fed about 1/2 of what I put in this month. I bumped the input significantly this month to test the waters and see what I could get away with.

As always, I'll keep the spreadsheet updated daily at this link if you want to check in. 

Comment by Ben on April 1, 2013 at 2:10pm

Whoops, my bad. I was looking at the wrong column. I front loaded the system on 3/6 and 3/7 with ~12.5 pounds total over 24 hours... not 14 lbs at once!

I guess that's a good sign I need to work on the formatting of the spreadsheet. :) 

Also, this is the full month tally for March, including the normal compost heap:

Compost Pile & Worm Bins: Mar-13
Food Scraps 46.55
Coffee Grounds 342.65
Carbon Materials (paper, cardboard etc) 14.45
Other (Leaves yard debris, grass clippings, etc) 50.85
Comment by Farrel Stauffer on April 5, 2013 at 1:52pm

This is great information Ben!  Based on your experience so far I think I can get by with a VB24.  I guess if I find I have more waste I can always build another one.  I haven't had any difficulty with heating up yet.  That may be due to smaller amounts of food waste going in the bin at this point or the fact that we store our veggie trimmings in the freezer until the old ice cream bucket gets full (about once a day).  Keep up the good work!

Comment by Ben on June 5, 2013 at 8:38am

After the first 3 months, this is what the results look like on the VB24. I had a bedding-tossing-induced heat up in April which resulted in my opting NOT to feed for a week and a half, hence the lower figures. I think the March feedings are probably about max for a bin this size. To be honest, the only reason it didn't get more food in May was because I ran out of food scraps and hadn't been collecting much in the way of grounds. 

VB24 Worm Bin: Mar-13 Apr-13 May-13 Jun-13

Food Scraps 44.6 23.4 32.0 3.5
Coffee Grounds 17.1 5.7 6.2 3.1
Carbon Materials (dry) 2.7 2.2 2.0 0.0
Compost 0.3 0.0 0.0 0.0
Leaves 3.9 0.3 4.0 0.0

I've since remedied that food shortage and currently have ~30 lbs (evenly split) of food/flower scraps and coffee grounds from Starbucks aging in a rubbermaid. I removed ~2 lbs of worms in late May, so there may be a slight slowdown in processing speed until the population rebounds again. Given the age of the bin and the number of "breeders" currently active, I don't anticipate that taking more than 2-3 weeks max. 

I'm hoping to get a second, modified, VB24 built later this month. I'm actually planning for it to be about 1.5 times larger, so a VB36 if you will. (Volume of ~60 gallons rather than 45) And I'll likely make it a standalone box with a stand so it can be moved more easily. I am in a rented place after all, so having one that won't be TOO heavy (and/or is on wheels) is going to be important when moving time comes. 

Comment by Andrew from California on June 5, 2013 at 10:18am
Apart from the worm removal last month, have you removed anything else...VC?
Comment by Ben on June 5, 2013 at 10:19am

Yes, yes I have. But I was a bad boy and didn't weigh it. I'd estimate I've harvested about 5 gallons of VC in the last 2 months. 

Comment by Ben on August 5, 2013 at 9:52am

Looks like I'll be suspending this spreadsheet for the moment. Owing to the amount of food I'm getting from the local Coop, the use of two bins, and to the fact that this creates more work... I'll be discontinuing the weighing for the foreseeable future. Feeding is usually a haphazard and/or rushed process as I'm doing other yard work and gardening. Adding extra steps (for now at least) without a scale I can just leave outside and zero out for a specific container or two... it's just too much additional work when I'll be disposing of several hundred pounds of waste per month now. Thanks Alberta Coop! Hope I can keep up with your output.


So here's the final tally, by month & bin. Compost is not added to the overall Waste Diversion total because that would be double counting. I use it in the bins, but it's technically already counted when I add it to the compost pile/tumbler. If you want to see day by day progressions, go here and download a copy to play with yourself!

Combined Compost Pile & Worm Bins: Mar-13 Apr-13 May-13 Jun-13 Jul-13
Food Scraps 46.6 23.4 34.7 30.3 180.4
Coffee Grounds 342.7 319.4 6.2 41.0 9.3
Carbon Materials (paper, cardboard etc) 14.5 18.2 2.3 2.8 16.2
Other (Leaves, yard debris, grass clippings, etc) 50.9 18.3 4.0 9.0 69.3
BIN #1: VB24 (45 Gallon), Insulated, Outdoor, manual harvest.
Food Scraps 44.6 23.4 32.0 28.5 34.8
Coffee Grounds 17.1 5.7 6.2 16.0 4.0
Carbon Materials (dry) 2.7 2.2 2.0 1.3 2.8
Compost 0.3 0.0 0.0 9.0 8.0
Leaves 3.9 0.3 4.0 0.0 1.3
BIN #2: VB42 (78 Gallon), Insulated, Outdoor, turn-harvest.
Food Scraps 0.0 0.0 0.0 0.0 55.5
Coffee Grounds 0.0 0.0 0.0 0.0 5.3
Carbon Materials (dry) 0.0 0.0 0.0 0.0 11.4
Compost 0.0 0.0 0.0 0.0 54.5
Leaves 0.0 0.0 0.0 0.0 48.0
Total Worm Bin 68.4 31.5 44.2 54.8 225.5
Total Waste Diversion: (Does not include compost added to worm bins) 454.5 379.2 47.2 83.0 275.1

Totals for 5 months:

Worm Bins:                        424 lbs || 193 kg

Compost & Worm Bins:    1,239 lbs || 562 kg

Comment by Andrew from California on August 5, 2013 at 11:32am

Well done, Ben! Have you talked to the co-op about setting up their own worm bin?


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