cycling a new tank

[tallchik77]

okay, this might sound like a wierd question but I gotta know! can I cycle a new tank without a filter? the reason I ask is because I have a fully established 55 gal already (been running for a year now) and I am going to be putting all my fish in a 20 gal (don't have very many fish). I will be eventually re-setting up the 55 gal in a few months when I can get together all the supplies. so, I started aquascaping and I was planning on using some substrate from my 55 to put in the 20 and I was ofcourse going to use the same water straight from the 55 and also ornaments. I know my 20 will probably go through a mini cycle because I do have new substrate but i was wondering if I can just go ahead and set it up and transer immediately or do I need to let the new one sit and cycle. I don't really have the funds right now to buy a new filter, which is why i need to know if it can cycle without a filter. sorry if this is all over the place but I hope someone can make sense of my post lol. would love any advice you can offer! thank you!

 

[Mark Hewitt]

So you are moving everything from the 55g to the 20g including the substrate and filter? Yeah that should be ok, as long as you keep the filter and gravel wet during the transfer, then you shouldn't even have a cycle at all.

I believe your second question is "Can I then cycle the 55g without a filter". Well the answer is basically no! Firstly, you don't cycle a 'tank' as such, but the filter, as this is where the bacteria lives (virtually none in the water itself) so you can't cycle a filter for the 55g if you haven't got one! Secondly in order for cycling to take place you need an ammonia source, either from having fish in the tank, or adding in fish food or pure ammonia.

The best approach for you will be to wait and not change anything (including moving to the 20g) until you have everything in place for your new 55g setup, including the filter.

Then you have two choices,
1) Move the fish to the 20g and use 'fishless cycling' on the 55g to bring it up to speed.
2) And this is the one I'd do. Get a new filter for the 55g and run it (perhaps on a low setting) on the 55g for 1-2 months, that way it'll cycle using your existing bacteria and ammonia source (the fish)
Then in one swift motion, set up the 20g and move across the your old filter and most of your fish to the 20g tank, the filter will be cycled so you shouldn't have a problem but keep an eye on your levels.
And then either immediately put new fish into the 55g or keep some of your existing fish in there to maintain the filter until you get some new fish and then move them to the 20g.

The thing to remember is that filter bacteria is like any other organism, they need food to survive, in this case fish waste, remove that from them and they'll die. As ever with fishkeeping there's usually more than one way to do things, but the most important thing is to look after your bacteria, as they are what looks after your fish!

 

[tallchik77]

im actually not concerned with re-establishing the 55 gal for a while. i just want to get the fish out of there and into the new 20 gal. so basically just need to know if i can just go ahead and put their water in it, with their filter and about 3-4 cups of their substrate without the tank going through a big cycle. i've only ever done a fishless cycle before and i dont want to hurt my fish. as far as cycling without a filter i meant could i cycle the 20 gal without one if i was using their water and things with bacteria on it so that i can cycle this one and keep them in the 55 gal until it was complete. i dont want to buy a new filter to do this but if its necessary then i would.

 

[BigJim]

Put the filter from the 55g on the 20g and I seriously doubt you'll see any kind of cycle.