Re: Fishless cycling or Pure bacteria balls
#2
The products which claim to curtail the cycling process do not (yet) have great evidence for effectiveness - a couple of them may have the correct nitrifying bacteria and thus are more likely to work than others but only if the correct procedure/instructions have been followed during the process from manufacture to use, which of course cannot be ascertained. In rare cases, they may work; in most cases, they'll make no difference, be a waste of money, and potentially cause confusion about where in the cycling process you are (and may thereby even prolong the cycling process).
Those in local aquatic/fish shops are trained to sell such products, as well as a whole host of other products to counteract the effects of incomplete cycles or ammonia/nitrite presence and high nitrates, medications for sick fish, and new stock to replace those which succumb.
The fishless cycling method using ammonia is the 'tried and tested' method proven to work, and, as yet, no product has been identified to compare to its effectiveness.