Bobberman
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Small compost boxes?

How big does a compost have to be to work! The answer to that is probably any size. If that is the case how about this idea! Once again it comes down to a insulated box which can have a few air holes in the bottom! Take a styrofoam box about 6 inches deep and mix compost maybe some rabbit manure and a little blood meal and line the seed growing table in your green house with these boxes. Now put your plastic seed growing boxes on top of these smalll compost boxes and the heat will do the rest! It can't be that easy! Another option is leaves on the top of the compost boxes about a inch thick then the seed boxes on the top of the leaves. The leaves will insulate slightly and hold more heat in the compost box. When the seeds sprout and the plants are ready to put out you will be able to use the compost formed in the styrofoam boxes! This is like a double benifit! There has to be a flaw here somewhere in my thinking. What do you think?

DoubleDogFarm
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Bob,

With a quick Google search, looks like one cubic yard is needed to retain heat.

https://www.iesitexasregion.com/index.php?option=com_content&view=article&id=175&Itemid=210


Eric

Bobberman
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I see what you are saying but has anyone ever tried a compost in a small box inside a greenhouse inside a insulated box! It seems to me that bacteria is working all the time under the garden even in the winter and generating some heat! the right mixture in any size should generate some heat and maintain itself under the right conditions! A small amout of heat is all you need to warm up a box even 5 degrees may do the job. I am sure that during the day the compost will benifit from the heat in the green house and continue to work at night. Its like a chain reaction it seems to me! I will reserch this much more. Thanks for the link! They make a small acquarium $2 glass inclosed thermometer that I can stick into the soil and monitor my progress with this set up. I will try this next week since I will be starting some seeds then! The solar greenhouse world has alot of new things that are on the horizon and I want to be part of I!

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soil
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have you done this or are you just thinking theory.

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applestar
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Was wondering the same thing -- maybe the thread title should end with a "?" to be more accurate.... ?

Bobberman
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soil wrote:have you done this or are you just thinking theory.
+++ No I have not tried this compost in a box but will do it next weekend when I start some of my seeds for this coming year! I will pobably start with cole crops in this cold weather since my solar house is staying abou 30 at night even with the outside temp at 15!

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rainbowgardener
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You have a very inventive mind, Bobberman! I like how you are always looking for new ways to do things.

My concerns about this would be two: The one I mentioned before re the compost in the pipe, that it wouldn't be very aerobic. Even with some holes it sounds like limited air circulation. You could get stinky sludge instead of compost and there could be some nasty bacteria in that sludge. Second is the one Applestar mentioned earlier about the styrofoam readily leaching out nasty chemicals.

In general, I say try the experiment. But in this case, you wouldn't have any way to test at home to know if you were producing harmful chemicals/ bacteria.

The Helpful Gardener
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One of the reasons commercial composting happens so much faster than backyard style is simply a matter of quantity.

THe bigger the mass, the bigger the bio-mass, the more heat, which translates into more bacteria, which is more food mass for protozoa, more nutrient conversion and weak acid reaction, etc., etc., etc.,...

So, in composting anyway, bigger is better. Could it be done smaller? Probably. But go with as big as you can for best results...

HG

Bobberman
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I agree that a bigger compost is better. I have heard the word nano which I think is how you spell it which seems to refer to small very small things! I think this will be very interesting to see if much heat comes off a inclosed compost inside a insulated box! The heat must go up and I hope it helps the plants. The other thing here is that organisms give off carbon dioxide in a compost and this air is needed for better plant growth so maybe it will work even better than I hope!!

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farmerlon
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Your idea is interesting.
The suggestion that a compost pile should be at least a cubic yard in size, is primarily to keep it working in outdoor conditions. For instance, in winter, the outer 6-8" (or more) of the pile might be frozen solid, while the interior of the pile is still over 100 degrees and "working".
Also, as HG mentioned, the larger piles with greater biomass can be more effective.
But, I will be interested to see reports of your experiment.

As for the box, I believe you would have better success with a little more depth... maybe a minimum of 12", instead of 6". The material will reduce in volume as it composts anyway.
Also, how about making the sides of the box (that touch the compost) out of wood? (not treated wood) That way, you don't have the chemical concerns from the styrofoam. You could make a box-within-a-box, using the dead air space between the 2 boxes as insulation. Or, use foam insulation between the 2 boxes. Or, use a single box with foam attached to the outside for insulation.

just my 2 cents ... best of luck with your experiment! :)

The Helpful Gardener
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I am also somewhat concerned with the word "enclosed" as in closed up.

Composting (at least the type that doesn't involve fecal coliforms and E. coli) is an aerobic process; the more air the better. The more we "enclose" the more we exclude air. Unless you are going for a specific anaerobic process (bokashi, anyone?), there may be unintended and unwelcome results with your admittedly carbon dioxide rich process. Add in the offgassing of the styrene and we have a noxious and decidedly anaerobic situation...

It will be an interesting experiment, but I foresee mostly interesting ( :!: ) smells... :twisted:

HG

Bobberman
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When you think of something like this there are so many variables! Does a compost really need alot of air I am not sure. When a compost is working it lives and diesin areas as the temp gets to high or too low! The air maybe just cools it! What is being composted also makes the smell. There is sort of a composting in our own bodies and a person that is a meat eater find out that there is more smell than a person that is a vegetarian! I plan on using a garden soil or a fisnished compost material and add blood meal or a compost starter! When you burry a animal it decomposes without air. As a matter fact most people don't know that maggots can live in a closed container without air where meal worms can't.. The world of compost is just like the ocean and needs more reserch! Even the very deep depth of the ocean we find creatures that live on methane at depths where there is no light! Burning styrofoam is very hazzardous but as a glass for water or a contaier for dirt I see no problem. I do agree with you than mixing pieces of styrofam in the garden is bad for the enviroment because mainly it floats and will pollute the streams. Oil on the other hand actually is eaten by creatures in salt water which I did not know till this past year! Maybe they will also eat styrofoam who knows! Thanks for the input I do appreciate what you are saying and will keep a open mind!

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rainbowgardener
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Yes of course there is anaerobic decomposition. It's not what we usually call composting though. Here's a little bit of info:

Anaerobic Compost is made with organisms that do not like air. These are the creatures that in nature do their work in the dank places we humans tend to avoid. Swamps, bogs, deep cold lakes etc. They will work on compost, but they work slowly. They tend to release noxious gases that are quite disagreeable. If you have ever left a bag of grass clippings and then tore it open a week later you have had a close encounter of the third kind with these creatures....Anaerobic piles will tend to have more likelihood to have an overabundance of nitrogen causing the dark slimy feel due to the fact that the organisms in such a pile have less of a need for nitrogen and high energy. They work slower, and the nitrogen will tend to convert to ammonia making a bit of a smelly mess. https://www.rivenrock.com/composttypes.htm

Anaerobic composting basically consists of piling up a bunch of organic materials, then letting them sit and rot, [while covered]. Pretty gross, huh? Well truthfully, yes, it is. Anaerobic bacteria are slow and inefficient, which means that your compost pile will have to sit there for at least a year, maybe longer, before the materials at the very bottom are fully composted. Second of all, microbes that do the decaying in anaerobic composting produce methane and sulfate gasses as a byproduct, something which we humans find very offensive. https://tomato-tips.com/aerobic-vs-anaerobic-composting-whats-the-difference.html

Here's a little bit about your styrofoam:

What is it?

Polystyrene is a petroleum-based plastic made from the styrene monomer. Most people know it under the name Styrofoam, which is actually the trade name of a polystyrene foam product used for housing insulation. Polystyrene is a light-weight material, about 95% air, with very good insulation properties and is used in all types of products from cups that keep your beverages hot or cold to packaging material that keep your computers safe during shipping.

Why not use it?

The biggest environmental health concern associated with polystyrene is the danger associated with Styrene, the basic building block of polystyrene. Styrene is used extensively in the manufacture of plastics, rubber, and resins. About 90,000 workers, including those who make boats, tubs and showers, are potentially exposed to styrene. Acute health effects are generally irritation of the skin, eyes, and upper respiratory tract, and gastrointestinal effects. Chronic exposure affects the central nervous system showing symptoms such as depression, headache, fatigue, and weakness, and can cause minor effects on kidney function and blood. Styrene is classified as a possible human carcinogen by the EPA and by the International Agency for Research on Cancer (IARC). A voluntary compliance program has been adopted by industries using styrene. The US Department of Labor, Occupational Safety & Health Administration unsuccessfully (a federal court overturned the ruling in 1992) tried to limit the amount of worker exposure to styrene to 50 parts per million (ppm). According to the Styrene Information and Research Center (SIRC), they still encourage their member companies to comply with the 50 ppm exposure limit. This program would reduce styrene exposures to a 50 ppm TWA with a 100 ppm (15 minute) ceiling.
-OSHA (US Dept of Labor, Occupational Safety & Health Administration)
A 1986 EPA report on solid waste named the polystyrene manufacturing process as the 5th largest creator of hazardous waste....· The National Bureau of Standards Center for Fire Research identified 57 chemical byproducts released during the combustion of polystyrene foam. The process of making polystyrene pollutes the air and creates large amounts of liquid and solid waste.
Toxic chemicals leach out of these products into the food that they contain (especially when heated in a microwave). These chemicals threaten human health and reproductive systems.

it goes on from there https://www.earthresource.org/campaigns/capp/capp-styrofoam.html

Also:

Polystyrene contains the toxic substances Styrene and Benzene, suspected carcinogens and neurotoxins that are hazardous to human beings. Polystyrene food containers leach the toxin Styrene when they come into contact with warm food or drink, alcohol, oils and acidic foods causing contamination and posing a health risk to people. Over 100 US and Canadian, as well as some European and Asian cities have banned polystyrene food packaging as a result of negative impact to humans and the environment. https://www.way-to-go.org/doc/PolystyreneFactSheets.pdf

Bobberman
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Very informative my understanding of compost is improving! I will be more careful of heated drinks & things in styrofoam containers!.

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farmerlon
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Bobberman wrote:... Does a compost really need alot of air I am not sure. ...
Yes, it definitely needs air. For the best compost, Aerobic compost is what you want (for all the reasons already detailed by RG above).
With your "box" concept, I assumed that you would manually aerate (stir or mix) the material now and then, to keep it aerated.

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M.Clark
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I use a 30-gallon black plastic garbage can with holes drilled in it every 5 to 8 inches. Often it will only fill up half way and I run a bit hotter mixture (beer grain, shredded paper, coffee grounds) but I found it will turn around in 4 to 6 weeks, sometimes less. It is on the south side of my garage in full all day sun, so the heat from the plastic also helps.

Have you thought about getting some red wigglers and doing a worm bin? Those don't have to be very big, can have amazing results, and if you keep them in doors they can go year round. I have been kicking around the idea of doing one in my house, but have not gotten around to it yet.

toxcrusadr
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Re: Compost for Heat
Probably 30 yrs. ago I read something about burying (fresh) manure under your cold frame to provide warmth to extend the season. I think the British were doing this a long time ago as their winters are not so harsh as the northern US. So, nothing new under the sun!

Re: Toxicity of Polystyrene
No argument here that styrene monomer and benzene have some toxicity. However, the actual exposure (amount over time) is going to be pretty small using foam sheets in a greenhouse. How long does a person actually spend in their greenhouse? And you have to consider other contributions. If my whole house is covered with the stuff, theoretically I'm breathing it all the time. Of course, any residual in the foam will outgas over time and drop off to much lower levels. And, the stuff would not be on the market if levels of styrene known to be toxic were coming off it. We don't know everything yet, but there are people watching this stuff. CCA lumber, formaldehyde, asbestos, the list goes on of things that were taken care of.

Having said that, I try to avoid using plastics for food, especially hot food, when reasonably possible just to cut down on all sorts of exposures - plasticizers are starting to worry me with respect to endocrine disruption.

It wouldn't bother me in the greenhouse though. I actually built a cold frame out of 2" thick foil covered polystyrene sheets. Grew some great veggies in that. :D



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