Fishless cycle using established filter- step by step instructions?

Are you running a new filter on the 5 gal for a while and then moving it to the 10 gal? Or are you setting up the new filter on the 10 gal and then just moving established media into it?

Either way, I'd simply add some ammonia to the new 10 gal (no fish in the tank yet) to challenge the biofilter and/or encourage the bacterial colony to expand to meet the demands of a larger tank. Just as with a fishless cycle from scratch, I'd then do a large water change to lower nitrates and finally stock the tank with a full bioload of fish.

Moving bacteria

What you are trying to do is to move the bacteria from tank A to tank B, without disturbing the biological processing in tank A.

Fill the new tank, new gravel, new plastic plants, fresh water, dechlorinated properly, new heater, water temp correct. Start the heater, see that it works and is stable as you expect.

From the Whisper filter on the 5 gallon tank, you ought to be able to put a new biobag into the old tank and remove the old bag to the new tank-- I am assuming that this is like my small Whisper, with a frame holding a bag that may or may not hold carbon. Although that bag can last for months and months, you can replace it from time to time. The remaining bacteria in the old tank; on the filter itself, the tubing, the plants and gravel, will ease the shock of losing the main home for bacteria in the old tank. Just don't clean the rest of the tank or filter at the same time. Remove the bag and very gently swish it off in a bit of tank water, it should be brown, but not gunky.

Take that old bag and cut it into pieces, maybe 1/4 and 3/4 pieces. Put the 1/4 piece inside the new bag you are using on the old tank, the bacteria will rapidly move to populate the entire bag.

Then do the same with the new tank filter, put the 3/4 piece inside the new filter bag -- I am assuming you will have a larger Whisper on that one, or maybe the same size. Set up the new filter in the tank and turn it on.

Now you can add a fish or two or 5. I'd advise adding the guppies first, only because I bought 5 guppies once, mixed sexes, and had 13 within the week, 25 within the month. I don't know how happy an all male guppy tank will be, but if you get any females, you need about 2 females to each male, or as I had, 2 males to 3 females.

The secret is to feed lightly or not at all for awhile. Food = waste and you need to allow time for the bacteria to grow. So, feed very very lightly, like one 1/2"x1/2" square flake to feed 5 small guppies, very lightly.

mishi8 said:

Either way, I'd simply add some ammonia to the new 10 gal (no fish in the tank yet) to challenge the biofilter and/or encourage the bacterial colony to expand to meet the demands of a larger tank. Just as with a fishless cycle from scratch, I'd then do a large water change to lower nitrates and finally stock the tank with a full bioload of fish.

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How much ammonia is "some" so that you know you have made the challenge and can feel comfortable that everything is set up OK?

Rava said:

What's the best way to add ammonia- such as, from what source? If I only have to do this once, I don't really want to buy ammonia if possible. What's the timeline for this process? Once I add the ammonia, what do I need to look/wait for before doing the water change and adding fish?

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I suggest buying ammonia for dosing. It's really cheap, and the leftover ammonia can be used for household cleaning. Buy ammonia that has no surfactants or scent...just ammonia and water (and maybe chelating agents) should be listed in the ingredients.

Dose ~4ppm ammonia in the 10 gallon if you want to develop a bacterial colony for a full bioload of fish. The filter on the 5 gallon may not develop a large enough colony for your 10 gal, so you may (likely) need to dose more than once. The timeline should be considerably shorter than a fishless cycle from scratch...anywhere from a few days, to a couple of weeks? Too many variables to give you a definitive timeline. You'll be looking for the biofilter to be able to consume ammonia and the resulting nitrite completely within 24 hours, leaving only a reading of nitrates. For full info on fishless cycling, check out this webpage: http://www.aquamaniacs.net/forum/cms_view_article.php?aid=31

FishInMaryland said:

How much ammonia is "some" so that you know you have made the challenge and can feel comfortable that everything is set up OK?

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If you're planning on adding a full bioload of fish immediately after cycling, then you want to add ~4ppm ammonia. Once the biofilter is consuming that, and the resulting nitrites, within 24 hours, you are good to go (after a water change to lower nitrates.)

You're welcome.