Many times, for those who have two double knots with eight strings in each knot (i.e. not following the opinion of the Rambam), the knot starts to come loose often, sometimes even several times a day. ...
Is it better to wear wool tzitzis? indicates that it is better Halachically to wear a woolen Beged with woolen Tzitzis. Recently I met a fellow who the entire week wears cotton Tzitzis, yet on Shabbos ...
In the response to List of Techelet Wearers it mentions a few Gedolim that wear Tzitzis of Techeiles on Shabbos only. Why would there be a difference between Shabbos and the rest of the week?