On 2009-08-10, Andrew Gabriel wrote:

In article ,
Tim S writes:

Is it the grout or silicone or something else that's sprouting the mould?

Grout won't grow mold, but it might have soap scum on it which is.
An old washing-up (or similar) brush will remove the soap scum.
(Probably easiest to do this whilst actually having a shower;-)
Use of liquid soap will stop the soap scum (although liquid soap
itself goes moldy, but hopefully it will wash off before that happens,
unlike the soap scum.) Alternatively, try one of the daily shower
sprays, which is a weak surfacant (detergent) and sometimes weak acid,
to help make the scum run off and/or dissolve before becoming encrusted.

What causes grout to work loose?