I've just retaken possession of a house which I let out, and now need to prepare it for new tenants.
There is a very large, odd and unslightly stain over most of the bottom (only) of the toilet bowl, black - grey in colour. Haven't a clue what it might be and wonder what the panel would recommend hitting it with first? Acid? Alkali?
It's a very soft water area (my own loos, nearby, have no problems at all). Toilet and all pipework in the property was renewed 18 months ago, and there are no water tanks (all direct mains fed).
Thanks David