Help I cant find Polypropylene bags in Mexico

I am finished buying my land in Mexico and want to start building but I cant find a supplier for bags or tubes here. I about to be forced to go back to the US and have to pay importation fees I would greatly appreciate anyone's wisdom thanks.

whoa, don't do that.  Where in Mexico are you? 

I am near Chihuahua City.  There are tons of bags up here.  You need to contact an animal feed dealer or a place that bags grains.  You should have one in the largest city within 100 miles of you.  They will be able to find you all the bags you want, though they might be a bigger size than the Americans use (40kg instead of 20 kg).

Up here, we call those bags "costales", and every cattle rancher around me has an old adobe barn full of them.

Thank you for the reply I will use this as last resort but I was hoping to get in touch with a manufacturer as I am planning on building twenty small houses for renting and also teaching Mexicans how to build these houses for free. I am trying to spread this method of building like a virus and I think I would need a consistent size of bag and a reliable source. The cheapest source for bags I've found down here is at around 3.5 to 4.0 pesos a piece, I might be forced to go to a source like you suggest due to price though. Once again thank you for the edification I hadn't even thought of that as a possible source. I have a few inventions that I would be willing to share with forum members that I will be using in my houses as well, they are as listed below
1. A 12 volt dc fridge / water heater conversion for RV size that uses only 127 watts for solar
2. A solar sterilizing not pasteurizing toilet able to flush toilet paper
3. A 60 watt house cooling system and atmospheric water generator using the earth as a main cooling source
4. I also have a source for atmospheric water generating machines that retail for 1600 to 2000 in the US here in Mexico for 500 us they use 500 watts when generating 
I'll give any and all of this info for free to people who will promise not to try to patent it and who will spread these techniques to the people who would benefit from using it. If we all get off the grid "they" will have to work or starve.   
 

I see uniformity is beneficial, but perhaps the people you are trying to help could appreciate gleaning a free and abundant resource rather than purchasing a new commodity.

I am interested in the house cooling system!

The house cooling system is very simple. Underground the temperature is usually about 30 degrees or so cooler than above ground on a hot day. You basicly sink some pipes underground force air through them to cool it and bring the pipes into the rooms you want cooled.  I got the idea when some for profit companies were doing a similar method in Georgia and were complaining about having to get dehumidifiers because all of the water they were making. I'm sitting here thinking why don't you start harvesting this resource instead.  The way to do this is as follows. Build a small box/ filter house the size of a doghouse  that will house the silver impregnated furnace filter a sixty watt box fan (if off grid you can use a panel and 12 volt large computer fans on each pipe) and large pvc pipes 6 to 8 inch or so (if you can afford the silver impregnated pipes even better). The pipes will start at the highest part of the building site if on a grade, if not you must slant down as you circle the house site with your trencher or bucket. Start by digging down to the three foot mark from the filter house and slant down as you run the pipes to about six feet at the lowest point (keeping about a foot between the pipes).At about halfway around the house very close to your wet wall or water storage/ filter station you will bury a food grade barrel  plumb it into the system and sink a low wattage sump pump make sure to leave the barrel accessible for later. Finally you start slanting the pipes back upwards going vertical where you want the pipe to enter the house near the ceiling of each room, be sure to super insulate any exposed pipes if its not a new build. The longer the pipes are underground the more the slowly forced air will cool. Its even good to throw in a few unnecessary seeming turns and bends into the pipes as this makes the air inside swirl and cool more efficiently. While laying the pipes its necessary to string a length of poly or nylon cord inside them, try to get food safe cord. The cord will have enough slack in the filter house so that once every month or so you can tie a towel soaked in a food grade hydrogen peroxide solution at about 3% and pull it through the pipes making sure you don't grow mold. That's it you bury the pipes at a v slant at the bottom you collect the water that condenses. Each building site is different so there are no real plans for this one but if you need me to draw a sample layout I can just pm me.         

Cool!  Silver impregnated pipes, I will check that out.  Thanks!