Colloidal Silver is an antibacterial and will kill the good bacteria along with the bad. Also it should not be used for more than 7 days at a time or it will loose its effectiveness as a treatment. You may want to try p b & c shakes ( psyllium , Bentonite and liquid caprylic acid). This is an extremely effective candida killer. Now I cannot say much for Colloidal Silver since I have never taken it. But I have not heard much about its success for candida.
Loading up on probiotics will not get rid of candida. You need to clear away some of the candida in the lining of the intestine to open up room for healthy bacteria to attach. Otherwise they cannot attach and they do no good.
Try pbc shakes then occassionally leave out the caprylic acid and replace with probiotics mixed into the shake.