I have been so pleased that Sainsburys value washing powder was getting rid of stains & is so cheap but recently I've noticed certain items looking a bit dingy & grey. I always wash whites on their own so its not from colour run so I'm guessing cheapo washing powder doesn't have brighteners in or something like that. We have great trouble finding a washing powder to suit us all so I was so happy to find that it didn't bring anyone out in a rash but as its biological kept the washing machine all spinky spanky. So is there anything I can add to it just for the whites wash to keep them bright?