David Hill wrote:
:: Not wishing to be pedantic but the OP did ask for "some kind of
:: moisture sensor" Singular.
::
Pedant over?

:: You are talking in terms of several.
::
Because he is looking for somewhere to buy *some*...BTW, just because I
supplied 3 different links, do you assume that the OP wants to buy three ! -
he asked for info, I supplied it, get over it.

:: If several then yes he can be selective regarding where and when
:: water is applied ...System allowing.

Read the post again (and the subject header for that matter)