Brown Stains Bottom of Toilet
Had brownish stains in the bottom of two of our toilets, thought it was the porcelain eaten away due to color and texture and what appeared to be the raw ceramic/clay showing though. After reading everything in this blog, simply turned off water to toilet, flushed, soaked up remaining water with rags and filled with CLR (since found out ZEP has same product for about 20% less). Let it sit, took small flat screw driver and gently scraped under edge of the brown stuff, it popped right off in flakes. Continued to do same with larger, easily accessed areas then followed up with small, hard bristle, non-abrasive brush. Turned water back on and flushed- eureka, just like new.
Based on what I've read and not having hard, iron saturated water, my guess is that a combination of what little iron there is in the water, combined with my children not flushing their urine consistently, a calcium/lime/rust build up occurred. Unfortunately I didn't take before and after photos to post, but fortunately it worked.
Thanks for all postings,
FRO