Hi all, I currently have 2 tanks running, a 110ltr and a 70ltr. Both tanks were started from scratch nearly 2 years ago using household ammonia and took about 8 weeks to properly cycle. They are both doing really well thank you very much.
So to my query...I have acquired a third tank and my LFS have told me the easiest way to set it up is to take some water from one of my existing tanks along with one of the spare sponge filters that I have had running for the whole time and that's it I'm cycled!!
Not quite......it will have a cycle sufficient for a few small fish, but that's all. Forget the water as it doesn't contain any beneficial bacteria, which all live in the filter media.
In a stocked and cycled tank, there will be just the right number of bacteria to process the waste of the stock in the tank. So if you take, say, a third of the tank's media and use it to set up another tank, you have enough bacteria for a third of the original tank's stock.
This is in theory though, as there's no guarantee that any specific piece of the media will contain any bacteria. The best way to approach it is to take some media from the existing tank and put it in the new tank's filter and then dose with ammonia as though doing a fishless cycle. If after 24 hours both ammonia and nitrite are at 0, you're good to go, if not, continue with a fishless cycle, which will be quicker than one started from nowhere.
Remember also, that the tank you take the media from will need close monitoring until the bacteria in there have reproduced back up to the full complement for the stock.
Thanks for your reply and good advice which I will follow.
I did start a new sponge filter in my 110 a week ago to replace the mature one I'm going to put in the new tank. How long roughly should it take for a colony of bacteria to build up on this? I'm thinking I'll leave setting up the new tank until this new filter has matured so as not to compromise the 110.
Unfortunately it won't mature because the number of bacteria present is limited by the food available. So with a steady stock level, once cycled, there will be no additional growth of bacteria.....removing media at any point always depletes the donor tank.