give it another try next time you ned to cycle a tank. It does work. I have the tank set upjust as it will be when I add fish, with lights heater plants etc. Add water from the tap but do not add de-chlor. Let filter and air stone run for 24 hours then seed with bacteria from another tank (gravel, old filter medium plants etc) and start adding your ammonia. Full cycle takes me from 12 to 18 days.
Cheers - Merrilyn