Hi all,
I am planning on having my 120 gallon tank set up my end of December so possibly ready by beginning Februrary. I had some ideas about cycling it and a few questions (if there's already a thread on this topic let me know).
Firstly; tonight I changed filter-cartridges in all three tanks- they all have room for two cartridges and I only changed one. I am wondering if it is possible to save the cartridges and use the bacteria while cycling my new tank? Would freezing them kill the bacteria? What about in a sealed tupperware full of water? Or do "they" need food and fresh water?
Second; If it is possible to save the cartridges for a month and a half how would I go about getting the bacteria into the new filters? I thought of soaking them together in a bucket for a few days. Or possibly just putting the cartridges in the tank and "letting the bacteria loose" lol. The filter for the big tank will obviously be too large to use the cartridges from my "small" tanks.
Lastly; I am planning on cycling the tank by letting a shrimp or possibly small piece of raw fish rot in the tank, anyone had success with this method? I read about it in a few books. Can the process be sped up by dumping "used" fish water into the tank? If I do a large water change on all three tanks the day I set up the new one I could have over 50 gallons "used" water for the new tank.
Do forgive me if these are ridiculous questions or if they have already been answered elsewhere.
Thanks for your help!
CheriAlex

When cycling I would do some water changes and wait. Its not really something you can control. You couldtry the rotting thing but Ive never tried it.

Freezing them will kill them. The bacteria should ideally be kept in a tank (of course) but you could have them in a bucket or plastic container with an air stone, if you need to keep them for longer, otherwise you could simply wait until you'll have the tank before you change the cartridges.

Soaking the new and old cartridges in a container isn't going to do anything You could try putting the old ones into the new filter simply, 50-50 and then the rest of the filter will be populated by beneficial bacteria in time as they'll spread. You could also try burying the filter pads in the gravel and hope for the best.

I had a little bit of "old" tank water when I set up my larger system, I also took the gravel from the smaller, cycled tank. Then I let a few of the fish into the big tank after a few days and after two weeks all the fish had moved in and the tank was cycled.
I've read about the shrimp/fish piece method as well, but I never tried it myself. You could try adding fish food to the tank daily instead of putting the raw fish/shrimp there
After a week of it being set up you could introduce some of the fish (after a 50% water change) and then monitor the ammonia, nitrite and nitrate daily and change 50% whenever needed Remember to add beneficial bacteria, like Stresszyme, Nitrivec, fluid bio filter media or similar products every time you change the water! (I added a full dose of fluid bio filter media with every water change rather than just dosing the new water.)

You're welcome They would survive, but you could throw these filter cartridges away and just change some again once the tank arrives

Your fish would of course get stressed while the tank is cycling, but the same thing will happen if you'll cycle it without fish, once you introduce the fish to the tank (has to be done gradually! Like 3-4 fish a month) because even if you'll have the fish food/shrimp to create ammonia in the tank it won't be even close to the amounts goldfish produce! So in the end, I'd add the first few fishes to the tank after the ammonia goes away and then monitor the water quality until it cycles, later introduce the rest of the fish slowly so that the filter can get accustomed to the biological load

So from reading what you guys have been saying, if you did a complete fishless cycle, when you add a fish, would you then create a mini cycle as it were? Or would the tank have to cycle again?