I was breaking up some hpoo to do a GT monotub and figured Ild post a little pictorial since I see a lot of questions about the texture, type, and prep of horse poo for use as a substrate. Im sure this has been already done but it certainly cant hurt to have some pics. Mods if you feel this should be moved feel free. Firstly, find a good source of HPOO. If you live in the country the answer is obvious, but even in a metropolitan area theres still farmers, or individuals that have horses for recreation that live on the outskirts of the city that are more then happy to have you come take all you need for free. Check craigslist, its a great site. Search for Horse Manure. If you dont get any posts then try posting an add yourself. Horse Manure Wanted. If you will come get it, theres plenty that are willing to let you have it. As for the type of nuggets you want, you want nuggets that are leached and dried. They should crumble in your hand like you'll see in the below pics. If they are to old, they will crumble up, feel, and smell like dirt. It will be obvious. If they are too wet ... they will feel, and smell ... well ... like shit! Properly aged horse manure really has no smell or more of an earthy smell, and crumbles up into a nice fluffy consistancy that has little pieces of straw and fibers in it. Once you have the proper nuggets simply break them up by hand in a bucket, I use a 5 gallon for this purpose but anything will do. Break up all the chunks until you get a nice, fluffy consistancy. Make sure to completely break up all the little pieces so the mycelium can quickly colonize it later. Some of the nuggets may be a little to old and dry, and some might still be a little moist inside. Its really no big deal as long as most of them are properly aged. If you get one a little moist just break it up nice and softly and fluff it up as much as possible. If you get one that resembles dirt, hell I still break it up and grind it in my hands to mix right in. If theres any pieces of grass or even some leaves that came along for the ride, I know most would say to pick that stuff out... and you certainly can .. however I just break up any old dried grass up into pieces and crumble any dried leaves up and mix it all in. Consider it additives. I havent had any problems doing it this way its all getting properly pasturized anyway. It should look like this once you get it all crumbled and fluffed up. This is a little less then I use for a 64 qt monotub. Usually I look for about 7 liters of crumbled horse poo for that size of tub. Once I get about 7 liters of hpoo I add 2 quarts of verm, and 2 cups of powdered gypsum to it. Dump it right in the bucket, and mix throughly. If you like you could add a quart of worm castings or spent coffee grounds, but it isnt needed. I take approx. 400 grams of compressed coir and break it up into pieces and put it on top of the hpoo mixture. I boil 6 quarts of water on the stove, and pour it in the bucket over all the contents. I then put a lid on the bucket that has some holes drilled into it and cover with a towel. The temps stay very hot for quite some time. In my experience it usually takes a full 24 hours for it to cool enough to be spawned. It easily stays above pasturization temps for a good 5-6 hours or so. This could be considered semi-sterilization. This is a great way to pasturize bulk substrates. Although I like to simplify it by just pouring boiling water into the 5 gallon bucket and let it sit. Coir in itself usually is pretty clean. Many people use it without any pasturization at all. Once we dump the boiling water into the bucket, the coir expands and seals in the hpoo and the other substrate materials that do need pasturization. It keeps them hot by creating a blanket of coir over the surface, so to speak, trapping the heat in the lower portions of the bucket along with the more vulnerable substrate materials. Once its sat overnight to cool, take the lid off and mix it up by hand. usually the moisture content will be right on but if it seems a bit wet I simply take it into a bathtub and dump it upside down to see if any water runs out of the holes in the lid. If nothing comes out I know Im close enough. From here it is ready to spawn and go into monotubs, trays, or any other fruiting technique you want to use. If it is a little to wet you can simply squeeze it out a bit while you are spawning. I use lots of spawn and Ive noticed that the quart jars of colonized wbs are pretty dry and they seem to use up any excess moisture pretty quickly during the spawn run. So grab a tub, cut some holes in the sides, wipe it out with alcohol and lay a trash bag down in it. Sprinkle down some WBS spawn on the bottom, gently lay down your hpoo mix layer and continue to layer hpoo with wbs spawn until you only have one layers worth of the hpoo mix left. Then simply double up your spawn on the last wbs layer and lay down your final hpoo layer on top. I like doing it this way so it forces the mycelium to grow vertically rather then horizontally. Horizontal growth can often times form a matt on the surface that is not as effecient at developing pins. I like to cover the tub with some towels or a blanket to block out the light and keep the gas exchange to a minimum. After a week to ten days or so the mycelium will have completely colonized the surface and in many cases, is already knotting and pinning before I even introduce it to light and fresh air. ......... a few days later .... pins. Getting pretty in there ... and 12 hours later ...... BLAM! Still has a little maturing to do but was looking sexy so its close enough. Probably harvest in the morning although then it will probably be TOO late. Damn things always hit the sweet spot in the middle of the night it seems. ........ and finally .... 6 hours later ... HARVEST A few attempts at some artistic shots: Hope this helps some of you that are intimidated by the almighty poo, it really is the top substrate material in my opinion for yield and potency.