I have just tried to cycle a tank using the fish-less method, and i would not advise this to anyone, test kits that are availible are a huge waste of time as they are not reliable and accurate, so doing fishless is extreemly hard, becuase you are in a sence cycling blind, whereas fish in cycle which i have used before and have had success is a much better method, not for the fish, i give it that. Although your eyes are your test kits, watch the fish, see how they behave, if any are dying etc, slowly increase the fish load over weeks/months, use a hardy fish like white cloud mountain minnows, zebra danios(as mentioned above) or guppies. feed sparingly and perfom water changes every 2 days, about 30% should do it.