Less than five gallons = no cycling?

[cathy_n]

From http://en.wikipedia.org/wiki/Siamese_fighting_fish#Living_conditions

"Although small tanks are often sold with filters, tanks with less than 5 gallons do not cycle and bettas still require regular water changes to prevent ammonia buildup."

I do not understand how any container of water, given ammonia and nitrite, could fail to eventually produce nitrate. That is the cycle as I understand it.

Is it that a small tank will not properly detoxify all the ammonia and nitrite in the water in a reasonable time frame?

I am curious, as I am hoping to cycle my 2.5 gallon tank. I added ceramic beads to the filter mix to give more places for beneficial bacteria to live. I have live plants and driftwood in the tank, which adds even more surface area for bacteria. The water moves around slowly (because my betta hates it fast) but constantly. Why would this tank not cycle?

Thank you in advance.

[kaybee]

In my opinion, there is information on wikipedia which can not be taken as absolute fact.

A 5gal can indeed be fully cycled.

I fishless cycled my 5gal to the point where it could process 8ppm of ammonia in a 24hr period.

I could see how a small tank could 'remain' uncycled. For example if one were to do 80%+ water changes every couple of days, the tank may not have the opportunity to fully cycle since ammonia is being removed before it can be process. But even then, the cycle is occurring to some degree.

[Evil Slimy]

Urm... I would expect anything with a filter to be able to cycle.
I haven't tried it, but conceptually I could see a small tank, like a 3g without filter, cycle but not have enough surface area to maintain a large enough bacteria population to make a difference.
Still... in that case it would be misleading to state that you can't cycle a small tank.

[Gemini]

Bull dust!!! I have nitrates in my 5.9G!! Ammonia and nitrites 0, nitrates <10ppm. But definately not 0!!!! So if they don't cycle then my tank is just magical ;).
Wiki is sometimes (often) not to be trusted....

[Ryuu]

Yeah, wikipedia is a horrible site for acurate information. When I first started the hobby back up, I went to wikipedia for bloating, and it said to cut the fish's gills and drain out the watery fluid... yeah not good...

[cathy_n]

In my opinion, there is information on wikipedia which can not be taken as absolute fact.

A 5gal can indeed be fully cycled.

I fishless cycled my 5gal to the point where it could process 8ppm of ammonia in a 24hr period.

I could see how a small tank could 'remain' uncycled. For example if one were to do 80%+ water changes every couple of days, the tank may not have the opportunity to fully cycle since ammonia is being removed before it can be process. But even then, the cycle is occurring to some degree.

I guess I wasn't clear?

The article in Wikipedia claimed that tanks smaller than five gallons could not be cycled. You have a five gallon tank, therefore (at least according to Wikipedia) your tank can cycle.

Seems like most of the replies I got so far are from people with 5 gallon tanks (or larger). I'm curious if anyone has successfully cycled a smaller tank? Say 3 gallons or less?

My tank has a filter, but it is mechanical (sponge) and biological (ceramic beads) only. No carbon. I set it up that way with the intent to cycle the tank by pulling water past the high bacteria concentration on the ceramic. If it's not possible for this to work, then I will switch back to the filter media that has the carbon in it and continue my twice-weekly partial water changes.

PS - I have a nitrite and nitrate test kit coming in the mail, I hope to see soon if my new tank is producing nitrite now. If so, then I will see in time if it will cycle!

[Ryuu]

I have sucessfully cycled a 2.5 gallon tank.


EDIT: 1,400th post WOOT WOOT lol

[Gemini]

I've cycled a bowl which was only about 5 litres. I don't know gallons for that. From my understanding as long as you have an ammonia source, water, filter, material for bacteria to grow on the water will cycle. I guess though maybe it's harder to cycle them because there's less ammonia being produced, therefore less nitrites and less nitrates.
You don't need carbon to cycle. The bacteria will grow on the sponge and bio balls/rings.

[Evil Slimy]

I have a 3g fry tank with sponge filter and a 3g shrimp/snails tank with eclipse hood. Both are cycled and both have filters.

[GouramiGal]

I'm cycling a 5 gallon now. Once it's ready, I'm getting a betta. I only started on friday, so it's gonna be a while!

[cathy_n]

Thank you all for sharing your experiences with cycling a small tank. I am going to keep measuring levels and see if I succeed with my 2.5 gallon tank. :)

[Evil Slimy]

I'm sure it'll be fine. I personally think it's an old and now skewed myth based on bowls and tanks without filtration, where a small container wouldn't have enough surface area to host the needed number of bacteria to keep ammonia in check.
In this case the tank would in fact cycle as bacteria are not picky about tank size ( :ezpi_wink1: ), but give the impression it didn't.

[Scott_S]

I have also successfully fishless-cycled a 2.5 gallon hex with a Whisper HOB filter.

If you can keep water filtering through any size of container, I would think, it will cycle.

The water needs to be moving, as the bacteria also need oxygen to do their thing.

[cathy_n]

Thank you to all who offered their stories that kept me hopeful while cycling my small tank.

My 2.5 gallon tank did finally cycle. Ammonia and Nitrite consistently read 0 ppm and Nitrate is between 5 and 20 ppm. The tank is stocked with one male betta, one apple snail, and a few small trumpet snails in addition to some live plants. Once the Java ferns grow back to their original glory, the tank will be "complete".

Things I did which may or may not have helped:
1. I hacked my Whisper 3i's filter insert to remove the carbon and replace it with ceramic beads. Ceramic beads have tons of surface area for beneficial bacteria to grow.
2. I put a piece of driftwood in my tank that had been in a cycled tank. This may have helped with the bacteria, but it also gave my betta Ich. Stupid, stupid.
3. I took the betta out for two weeks for Ich treatment, thus reducing the bio-load in the tank.
4. I dosed the tank a few times with Cycle. The tank actually cycled about a week after I did this. Coincidence?

Things I did which probably didn't help:
1. I initially used the filter insert that came with the Whisper 3i. They're meant to be disposable, and thus I was throwing away my bacterial colony.
2. I changed the gravel because I didn't like the stuff I originally had. This also threw out my growing bacterial colony.

[terrapin24h]

we have a 3 gal eclipse that cycled just fine as well. It's now our hosp tank as we upgraded our two ADF to a 6 gal.

--chris

[Kula]

Eh, it's Wiki. In case you didn't know, most schools won't allow students to use Wiki as a source for information when writing a paper or doing any kind of research because anybody can edit the Wiki entries.

As the main Wiki page says:
Welcome to Wikipedia,
the free encyclopedia that anyone can edit.