Please, no plastic versus copper arguments, that's not the point of this post.
I've just had to clean the bath trap and noticed that a single Speedfit fitting is mouldy. Not just surface mould but it looks like it's well into the plastic, which has also discoloured to a sort of off white matt colour. I will obviously replace the fitting, but is this likely to just be a problem with this one fitting or something else? The rest of the fittings under the bath are fine at the moment.
Lee