I did a fsg job yesterday and had ran out of ubik, so had some stuff when i ran out last time which the person at the shop claimed was the same, just a different brand so i thought id give it a try. After rinsing off i noticed some yellow marks and went up to investigate. The water left behing was yellow and the water on the floor had gone yellow as well! Has anyone else had this happen or is it just me? Ill get the name if the stuff today, however i used it in a conny roof with no problems. Any ideas guys??