I'll preface this as I am a newbie with only about 2 months experience under my belt.

From what I have read isn't a worm bin much more of a symbiotic relationship between the microbes and the worms? The worms themselves don't really get anything from eating the food scraps (tea, coffee, squash, manure, etc.) but they subsist on eating the microbes and the waste products of the microbes. The microbes are the work horse of the bin in as much as they convert the food scraps. But the worms then create a better environment for the microbes to thrive both with the castings and the aeration.

I have read some people saying to avoid things like citrus and onions as these products tend to sit in a bin without breaking down fast. Just thinking about it I can see their point as both of these contain chemicals that inhibit decomposition - allimns are outright toxic to some animals (dogs) and contain a chemical that reacts with water to create a strong acid which is why you cry when slicing them, citrus has the acidity and the peels have oils which are used as wood preservatives. This hasn't stopped me from adding them but maybe I'll learn a lesson later on.

Can't dissagree with your composting C:N ratios sbryce, but I think we are dealing with more than just composting here. High temperatures can kill most worms but red wigglers are the Conan of the industry. And believe me, I have done my best to kill them with excessive heat.

For indoor composting, the main object for me is to rid myself of kitchen scraps and use the byproducts of that process. Peat moss media works just fine for me, and the composting process is not that particular as to C:N ratios when the worms are doing a major portion of the composting.

I have composted outdoors with fresh horse manure and straw bedding, along with a regular dosage of water and turning. The red wigglers have done fine even in the heat of summer.
The end product of my horse and cow manure composting with worms added, works well in the garden and raised beds mixed media. However, it is too strong for germinating seedlings.

I'm not sure what distinction you are referring to between bedding/food. I wasn't aware that I had made a distinction. Just figured I would break it down into categories.

In a worm bin the organic material is broken down primarily by microbes.

And re-reading your post, you talked about growing media, which we commonly call bedding.

Yep Morgan, and don't forget that you can't get high temperatures without large volumes. Hot composting is a cubic meter min recommended, any bin system feeding amount is going to be a tiny fraction of that (unless that's some bin!). Any local heating you might get is easily dealt with my worms just moving to your bedding or old VC in the system. I'm sure your horse manure had spots that were deadly, but worms just move to where it isn't and move back to eat once it's died down. Great thing with vermicomposting, it's all worm food in the end no matter how it starts out.

sbryce, when you say '1) Bed with high carbon materials and add high nitrogen materials gradually' I hope you're not mixing that in. It's what you shouldn't be doing, if you've got things like citrus you don't want to be spreading them about the whole bin unprocessed. And if you're not mixing, then you're not really changing the C:N ratio of the food you're adding for your cooling. 5 lbs of kitchen waste sitting on top of cardboard will heat up just as much as 5 lbs sitting on top of plastic because the C:N ratio of the food waste is the same since it's not mixed. You can have the correct ratios of sulfur, charcoal, and potassium nitrate, but if not mixed you don't get gunpowder.

So you're not mixing, then you've got what the general guides say. Have bedding, add some food to an area. The carbon bedding around the food you just dropped in isn't slowing the process down as it's not mixed in as mentioned above. It's just a way to avoid having to pre-compost or pre-rot food as it's then not the only place for worms to live. Kitchen waste isn't a worm home, rotted kitchen waste with it's bacteria and removal of anything dangerous is. Bedding (or old VC in older systems) is the home for worms while this change occurs, it allows the bin owner to do the rotting in the bin as it's only in a small area and worms have elsewhere to go.

As an aside, since many threads are actually on how to speed up the rotting process in the bin by chopping, blending, freezing etc. your scraps before adding, it also shows heating isn't really that big an issue.

Mr Yan, no problem with citrus in sane amounts. I wouldn't try 5 lbs of lemons for instance like your pears ;). They will take quiet a bit longer to break down but once they are done, worms work it over just like any other material.

If microbes instead of worms are responsible for breaking down organic material, then a bin without worms would decompose at the same rate as bins with worms...would it not!

I'm really not buying into this C:N ratio business for vermicomposting. Although it makes perfect sense for composting without worms, I don't see the need to be concerned about proper C:N ratios which can not be quantified in a ongoing system.

Remember with what I am saying all the experience I have is from reading right now. I have not done any of the studies or have much experience with my bins.

The worms feed on the microbes and what the microbes break down but the microbes thrive in the environment that the worms create. The microbes are both in and on the worms (think worm slime) and from the worm waste and are boosted by the aeration from the worm's movement. Without the worm the microbe levels would be a lot lower unless you moved back to the large hot bins requiring your turning them.

Some places I have read about this symbiotic relationship (there were other places I read this but can't find them now):

"The Role of Microbes in Vermiculture"

C. Bently speaks to this in many of his posts on http://www.redwormcomposting.com/

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I agree with morgan3 and don't understand the C:N ratios with the worm bins. The part where local heating within a bin being terrible confuses me too. Here I am assuming that you have a bin large enough that the worms can move away from the hot area. If anything heating will signify a large spike in microbial load which will be good for the worms to eat once it cools down. There's just no way I can see an established bin (30 gallon or so) getting enough biomass to support that level of micobial activity long enough.

Microbes need carbon for growth (reproduction) and nitrogen for energy, just like we need protein for growth and carbohydrates for energy. If you want a healthy microbe population, you need to provide both in balance. If you balance them too well, you will get a bloom that will cause heating. The heat is generated from the microbes metabolizing their food. If I spent all day doing nothing but eating and reproducing, I would generate a lot of body heat too.

You don't need to calculate C:N ratios. You just need to be aware of what is happening in your bin. If the bedding (high carbon) is mostly decomposed, add more. If you have a lot of undecomposed bedding, add food (high nitrogen). That is probably what you are doing already, so you should be fine.

mr_yan, good article which basically explains the symbiotic relationship between worms and beneficial aerobic microbes. I don't however see that there is any relationship between worms and C:N ratios which are useful in optimizing microbe activity in the composting process.

I guess what we are trying to say here is optimizing C:N ratios in vermicompost media makes the process more efficient.

Very interesting thread. I was given a vermicomposting box which did not have drainage holes but did contain organic material and some worms. I added lots of green organic material and shredded newspaper for bedding. At the end of a few weeks the pile had become a soggy mess and worms killed off. I've been a composted for decades and have managed pit vermicomposting sites. So this is an embarrassing admission that all that experience failed to prompt me to examine that gift box more closely.

marshallz10: What happened to you is what may happen to most all first time vermicomposters.

"lots of green organic material"
plus insufficient "shredded newspaper for bedding"
equals "soggy mess and worms killed off".

To most first time vermicomposters I would say
"Please add much more bedding and KEEP adding it
along with the food." To fix any problems add
more bedding.

_____

Our small bins do not need volume to get to
temperatures high enough to kill worms.
The temperature usually wanted and talked
about in a compost bin is way higher than
the high temperature we talk about in
vermicomposting.

Surface area would seem to be an important part of any bedding material. Where the weebeasties play best is in the slime between the food and the bedding. That is where the magic happens. The worms slurp it all up and deposit it in neat bibbits for us to use. These help soil structure.

I thought I had the right ratio of bedding to green waste but should have added more brown waste in the process. There are holes in the sides for aeration but no drain holes in the bottom. My bad for not checking. The worms are happy now that their environment is not water-logged.

Yep Mr_Yan, it`s in the relative quantities. What might be thought of as an overheating problem can also really be an overfeeding problem. A good feeding size in a bin isn`t going to generate enough heat to cook the whole bin. Under the worst conditions the waste itself might get hot enough that worms don't go there, but then they just keep away until it dies down. But that level of heat won't bleed into the rest of the bin at that temp and cook everything. 2 lbs of food into a 30 lbs bin won't cook it (think how hot that 2 lbs would have to get to raise the other 30 lbs to killing heat), 30 lbs of waste in a 2 lbs bin might, but really that issue is overfeeding. This is very different from hot composting where the generated heat is created everywhere and you don`t have that heatsink protecting the worms.

And like others who freeze, chop or even put into a blender our feedings as you see in other threads, we are actually trying to get them to rot faster which actually means more heat in less time. Faster it gets rotted, faster worms get to it, mine always warm up to some extent. Actually now that it is -15C (5F) outside and my apt is a little cooler, the worms are liking the warm bedding on top of the feedings hehe.

Marshallz, yes that's one thing with bins. They are so good at containing moisture that when food releases water as it rots, you'll be thinking that somehow you have a spring in your bin. Careful when adding high moisture waste like melons or broccoli stems. It's very different from an open or outdoor system.

The plastic tubs (4) which I use for indoor vermicomposting are located in an attached garage which is ambient heated. The garage never gets colder than 40F or warmer than about 50F in the winter months. In order to maintain sufficient heat I set these bins on top of a 6ft long heating pad with a thick carpet underneath. The heater is operated on a toggle timer which is adjustable in 15 minute increments. Controlling the heat can be rather tricky, so I'm careful to check the media temperature when feeding my worms.

I use 40F to 50F water to blend my foods before adding to the bins, and frequently use one more quarts of additional water for hydration purposes. The feeding process is typically two blenders full per bin and each bin is fed about twice weekly. This pretty much conforms to PererKs's formula and it works well for me.

There is one serious draw back to using a heater beneath the plastic worm bins. I must turn the bottom layer about once a week or it will bake. I usually do this when trench feeding and make sure there is adequate water to hydrate this material since it does get fairly warm. If this layer is not turned or hydrated it will bake into a hard crust.

I once left the heat mat on for nearly three weeks while out of town and baked the entire contents of each bin which I mentioned in another thread. I had one large cake with temperatures exceeding 100F. Instead of completely starting over I flooded each bin with water and after awhile I noticed worms while breaking up the bricks. Some were adults, but the rest were newly hatched.

When it comes to vermiculture mistakes, I have made more than my fare share, but vermiculturing with red wigglers has been more than forgiving.

I use a heat mat thermostat for my bins and can hook up to a total of 100 Watts capacity. There are newer ones with higher wattage capability and cost only a few $$ more. Got it from Amazon when it was on sale I think about $25 or so. Works very well.

Here is a link that might be useful: HEAT MAT THERMOSTAT

Back when I was keeping an iguana for 11 years (soap box: no one should buy an iguana as a pet nor should they be in the pet trade) I had a thermostat built into an extension cord with a probe for the measurement. This was capable of switching 500 W at 120 VAC and I still use it for my germination boxes.

The probe cable may be long enough you could place it within the bin and bedding slightly above the actual heat mat.

This looks significantly similar to my unit but I think mine is a ZooMed brand

I have an older model thermostat which I use with my four foot seed propagation grow mats. This unit is not designed to be compatible with other types of heat mats and specifically states that in the instructions. Your link Otis for the newer model stats that "The Hydrofarm Heat Mat ThermostatTM is compatible with all seedling heat mats." This might work with my six foot long heat pads from Growers Supply.

You still need to be careful to check media in the bottoms of the bins periodically. Unless the probe is inserted clear to the bottom of a bin, there is about a two or three inch zone which could heat up enough to bake the media even at desired temperatures.

I have often heard it stated that worms don't like to be disturbed, but I turn the entire contents of my bins about twice a month. Red wigglers don't seem to be bothered by this process, however I had problems with Euros using the same process as I do for red wigglers, and they didn't fare well.