Ivo Post scoops hog manure out of a Geotube at his farm Thursday near Maria Stein. The Grand Lake/Wabash Watershed Alliance is spearheading tests at two area farms to see if using Geotubes to separate manure from water is an economically feasible management tool for farmers. The liquid manure was pumped into three bags at Post's farm six months ago. Much of the water filtered out of the bag, leaving this moist, potting soil type mixture. Two Geotubes filled with dairy manure at another farm will be opened early next month.