I'm on day three of dosing the girls with duramycin-10 (for respiratory problem, different thread) with the recommended amount of 1 tablespoon per gallon. When I first mix it, it is pale yellow. By the end of the day, it's an absolutely disgusting looking brown! I sure wouldn't drink it, though the girls don't seem to mind. I checked the package and found the following: Note: This product is to be administered twice a day in the drinking water of swine, calves and poultry. One-half of the recommended daily dosage level of antibiotic is to be consumed during each administration period, thus providing the drug in divided doses. I'm assuming the antibiotic breaks down with heat/sunlight etc and doing half doses is a work around. So this morning I mixed up 1.5 teaspoons in half a gallon instead and I'll mix a fresh batch around 1pm. SO, if you tried duramycin with no success, maybe this had something to do with it?