I've got the 3M Color Quartz in about 16 of my 21 tanks and it never took me that long to rinse it. Several 125 g tanks, 250 g tank, 100 g, etc. I've got the dark brown, black, plum, brick-red...about every color they make except white. The dark colors stain my hands and arms but it rinses out better than the 1 bag of playsand I tried rinsing in the past.