Old filter media like you did is probably the best way especially when combined with some old gravel or décor. However if you put the filter media into the tank with no source of ammonia the bacteria will have nothing to feed on and will shortly die. So you need to put fish or some source of ammonia in the tank at the same time as the filter media. Then if you test your water and you have nitrate building, you know that the cycle worked.
I have also used "dr. tims", formerly called bio-spira, to cycle many tanks and It has not let me down yet.
yes its me with the 5.5 gallon that bought the 29 gallon. The 5.5 been running for 3 months now and has been cycled. i used some of the old media from there and went to my local pet store and bought 20 comets and put it into the 29... would the work ? if so how long would the tank take to be cycled ?Yes you can use cheap fish, it is recommended actually because even if you transfer the old bio-media, something could go wrong, or there could be a mini-cycle which takes place, which can be hard on fish. I'd recommend getting a couple feeder goldies to live in there and monitoring the water parameters until you have had no ammonia, no nitrite, and slowly building nitrates for a couple weeks. Then you can bring the goldies back and get the fish you want.
One thing I am thinking of- you were the guys with the 5.5 gallon previously right? And this is the new 29g you want to cycle?
Are you sure the 5.5 was cycled correctly and running with fish for a few months? If that tank wasn't cycled, putting the old media in the filter will not work, as it won't have the right colonies of bacteria
Thanks so much for your help man20 comets is way too many, I would recommend 5, the 20 will be putting out too much ammonia. If the bacteria from the 5.5 gallon lived and was successfully transferred to the 29, you should basically bypass the cycle process. You might get a "mini-cycle" during which you will see a little bit of ammonia and nitrite for about a week, and after a week you will have only nitrate. If more than a week or 10 days goes by and you still have any ammonia and/or nitrite, the cycle did not work properly, and at that point if your fish are living you should probably just let the cycle naturally run it's course, which takes usually 4-6 weeks.
But, the hope is that in a week from today, you will test your water and see no ammonia, no nitrite, and some nitrate (probably 20-40ppm). That is how you will know the tank is cycled.
No problem glad to help outThanks so much for your help man