TOTO Flapper filmy substance

I recently 2 months ago installed 2 Toto Drake Toilets. I started to notice some reddish particles floating in the bowl water. When you touch them they have a filmy/greasy consistency and dissolve in your fingers. I looked inside the tank and noticed the flapper had the same substance on it that was in the water in the bowl and when you cleaned up the flapper it removed the the filmy substance .It now appears to be building up this substance on the flapper again? I use no chemicals in the tank water. Any ideas what is causing this and do I need to be concerned.I never had this issue with the other toilets prior to the Toto install and I have done nothing diffferent in how I clean the toilets.

Does your water have a strong chlorine smell? Either way, call Toto, they'll send you a new flapper valve free. See if it lasts any longer. Mine seem to last somewhere around 3-4 years with our local water supply.