Mind you this opinion is based on hearsay and antidote evidence, no actual research study backs this up.
But it takes about 6 weeks to cycle up a system without bottled bacteria and it is likely to take you half a dozen weeks with bottled bacteria.
See, the bacteria we want to encourage is aerobic and if you seal it in a bottle, it isn't going to survive on a store shelf so about the best I can hope for the stuff is that maybe it won't hurt the system but why waste your money. If you want to cycle quicker, see if you can get the filter squeezings from a friend's healty aquarium or better yet some cycled up media from some local aquaponics system.
I agree with TCLynx. To start my cycling, I used water from an established, disease free aquarium that a friend of mine has. I added several gallons of his dirty fish water somewhere around 6/10?
Unfortunately I failed to test his water at the time that I added and do not have any results of what kind of numbers it showed. I added a few more gallons the next time he changed out the water but added fish to my system with the second round of water.
I went through the cycling process without losing any of my 10 feeders. I added those little guys on 6/17 and was fully cycled by 7/2. Both fish and plants are seemingly happy!
lots of aquarium "products" are only intended for ornamental fish, not fish you plan on eating!
and most "bacteria in a bottle" are bunk.. unless you're willing to spend some big $ for "fresh" processed bacteria
I've always used gravel from established aquariums to seed new aquariums with nitrifying bacteria so have never tried commercial bacteria products. But I think there are some on the market that work, like Bio Spira. I've read that the dogmatic Nitrosomonas and Nitrobacter actually very little to do with the nitrogen cycle in an aquarium (and, by extension, aquaponics systems). Rather, Nitrospira spp. do the lion's share of nitrification, and some commercial products have viable cultures of these. But why waste your time and money on these when you can just seed from a healthy, established tank.
I agree with @TCLynx I tried the bacteria supplements with urea at the fishless cycles and it still took me 6 weeks to cycle up the system. I don't think it helps but it doesn't hurt either. However, I use the dosage suggested for the fish tank. I wonder what would happen if I just put in the whole bottle. Hmm... maybe that something to try on my next system.