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How to cycle a tank?

1K views 29 replies 7 participants last post by  Mumma 
#1 ·
So I've been doing some research on cycling. I have had a 5gal since January of this year but I've read that cycling wouldn't happen in a tank that small and that it would just be best to do water changes.

But my bf got a 10gal last week and is a total noobie (not unlike me) so I thought that maybe we could cycle this tank. Thing is, the instructions that I've found online say to use a few small fish to get it started. We only have the one betta is the 10gal and we do not intend to put any other fish in there (nor do we want to). My question is, how do we cycle a tank that already houses a betta and about 10 shrimp?
 
#3 ·
The thing is, they always recommend using other kind of fish. I only have a betta in that tank and do not want anything else in it. How do I cycle a tank with just the betta and 10 shrimp in it?? I'm so confused.

Another question; can I cycle a tank using a sponge filter?
 
#4 · (Edited)
Yeah so far my Bettas have not faired well with a fish in cycle. I would recommend using the 5 gallon tank and monitoring the water parameters in it and doing a fishless cycle on the 10 gallon. This is my personal recommendation. Of course others have had Bettas and cycled tanks fine.

The thing with fish-in cycling is every fish even in the same species is going to react differently. Even in the "hardier" fishes they will sometimes lose 1 or 2 out of a school. With my Bettas I attempted a fish in cycling with I had one that almost died (got so weak he couldn't out swim the filter) and still fighting fin rot. The other guy I had developed slight fin rot that cleared up in a week with clean water. I kept the ammonia levels at .25 or below and for the first two week I kept them almost nil doing 80% water changes at the hint of ammonia. After 3 or so weeks in .25ish ammonia levels the fish developed problems. Also a fishless cycle will cycle faster than a fish in cycle as you can keep ammonia levels higher and offer the bacteria more food all at once to build the colony instead of a little at a time.

I'm not saying you have to do fishless, because I know myself was very much set on doing the fish-in cycle. I'm just giving my recommendations and trying to make it clear that with a fish-in cylce you have to watch the fish very closely. As some will have adverse reactions to even what is considered a "fish safe" level of ammonia over the extended period of a cycle.


As far as how to do it with fish in you do it the same with any other fish. Add fish and feed them lightly and watch the water parameters very closely do not disturb the filter(s) or substrate and anytime you see high levels of either ammonia or nitrite you do a water change. Some fish are recommended over others because of their reputation for being able to make it through cycles with survivors. These lucky fish get to be called "hardy". Some fish are not recommended such as ottos because of their reputation for being ultra sensitive to water conditions. Bettas fall somewhere in between hardy and ultra sensitive and aren't really recommended for or against. As far as the shrimp goes I do not know how they will take to the cycling process.

If you want to do the fish-in cycle and I understand that it's nice having the fish in the new tank all and maybe you don't space for the 2nd 5 gallon to be setup. I would watch the fish and water parameters very closely. Also be ready to put the Betta in a smaller QT tank (1-2 gallon) if he does suffer adverse reactions to the cycling process. These are suggestions and just presenting information with my recommendations. Hope no offense is taken.

Sponge filters work as excellent biological filters and work great as main or supplemental filtering. I personally use sponge filters because when I set up a new tank in the future it is very easy to seed it from a sponge filter.
 
#5 ·
Mike hit some good points. You can cycle a tank with a betta, but you have to be careful (as you should with any fish-in cycle). Just feed lightly, have a test kit on hand at all times, test the water daily, and be ready to do lots of water changes. You don't have to add any other fish.

Shrimp have a rather light bioload, so they won't affect the cycle that much. If you want to make the cycle easier on your little guy I recommend fast-growing plants like water sprite (floating), anarcharis (rooted), and hornwort (rooted). The last two are hit-or-miss for some depending on which exact species you get, but the water sprite is a sure bet. It will also give your little boy some cover under which to sleep and build bubble nests.

I highly recommend a bubble filter over a traditional power filter. Even with buffers some power filters are just too strong for bettas. Bubble filters provide just enough current to move water but won't blow your betta around. I use nothing but bubble filters in my betta tanks.
 
#9 ·
Hi
Does your 5g have a filter? If so I'd say it could be cycled.
Its not advised to add shrimp to a cycling tank. They are more sensitive to poor water conditions then fish. Even a tiny amount of ammonia could result in death. It's best to wait until the tank is stable to add them.
Any size tank can cycle. Even a 1/2g tank will cycle eventually. Smaller tanks are harder to fish in cycle (safely) because ammonia and nitrite reach toxic levels faster then in a larger amount of water.
 
#11 ·
That's the thing. It will be cycling or cycled. Even with daily water changes the bacteria will still be colonizing the sponge as they consume the ammonia produced between water changes.
If you have anyother tanks you can get a handful of gravel and add it to the new filter or hang it in a media bag next to the filter intake. That will help the cycle along.
 
#12 ·
I'm confused Mumma, you're saying that if I have any other NEW tanks, to add gravel from my current 5gal to help the cycling of a NEW tank?

So it is possible to cycle a tank with a sponge filter then? I will be getting a 10gal in a few weeks time. I am planning on cycling that one, probably fish-less. Another question, in a cycled tank, do I only do water changes when the ammonia spikes? If so, how much of a water change is appropriate?
 
#13 · (Edited)
Yes, you can add anything from an established tank to a new cycling tank and it will help speed up the cycle. The nitrifying bacteria affix themselves to surfaces in the tank. They live on the sides, decor, plants, substrate and mostly the filter. So moving some of these items to a new tank and adding an ammonia source (from a fish, bottled ammoina, shrimp, etc) will jump start the cycle. If you add enough 'seeded' media from an established filter you can instantly cycle at tank to handle a small bioload of fish. I have done this many times :)

A sponge filter will cycle just like any other filter. The bacteria prefer filters to colonize over other surfaces of the tank because of the higher water flow and oxygen available in the filter.

A cycled tank will not have any ammonia or nitrite. It will have rising nitrAte. Ideally you want to keep it 20ppm or under. When cycling a tank with fish there will be ammonia and nitrIte. When they reach 0.25ppm or more you need to do one or more water changes to keep it low. .25ppm of ammonia or nitrite will not harm the fish. Depending on the temperature and pH of the tank levels up to 1ppm could be safe. I recommended not letting it get that high just to be on the safe side.

When fishless cycling you don't need to worry if ammonia or nitrite get high because there are no fish in the tank to get harmed.
 
#14 ·
OK, I have a question... I hope this isn't considered thread hijacking!

I just received a new 5 gallon (yes, I'm now obsessed with bettas!) and would like to move the process along if possible. I do have another 5 gal that is cycled, but I don't want to risk messing it up by removing any of the gravel or media.

I'm wondering if it's possible to hang something in the cycled tank, like a bag of Fluval SPEC Biomax (just an example) that could then move to the new tank to help it cycle faster?

Yeah, I know, patience! But I have my eye on a new betta, but I don't want to get him and put him in the cycling tank, and I don't want to try keeping him in a medium pet keeper (which is the only other thing I have available) cause I hated the frequent water changes.

ETA: Oh, and how long would I want to leave the media in the cycled tank before moving it?
 
#15 ·
I don't know about the media thing, but if you change your water from your cycled tank, you can put it in the new tank to help..
For the media thing I'm guessing it might not work well.. Your cycled tank is already balanced with bacteria, and I don't think many more bacteria would be forming on a new surface. :/
 
#16 ·
I don't know about the media thing, but if you change your water from your cycled tank, you can put it in the new tank to help..
Honestly I would like to know where you have attained this info as its not true. Changing water from an already established tank will not aid or complete the cycle in any given way, most of the benificial nitrifying bactia survives and establishes where there is an exeptable amount of flow, and something to hang on to, like a filter in the media. Or in the case of an under gravel filter it will colonize in the gravel, not in the water. So just adding water from an established tank won't help much at all, your best bet is too just change a small percentage of the media. About 1 third will do

And to the real question, just letting media sit on the side of the tank won't help at all, but you can cut a small amount if media from the already established tank, that will help
 
#17 ·
****. xD I guess that is different. I used my uncycled 2.5 gallon water in my larger tank that I'm cycling to put in some more ammonia, I was told that would help, totally different from using a cycled tank's water.. Sorry.
 
#18 ·
NP. I was already planning on adding some water from my cycled tank to add ammonia. Yes. I do have an un-cycled 3 gallon that has the same type of filter, so I guess I could put that "used" filter on the new tank to give it a small jump start?

Unfortunately I have small internal filters in my tanks that don't have a good way to cut off, or remove part of the media. In the future I might look at changing the larger tanks to a HOB type where I can have either a bio-wheel or a unit that allows for various typed of media.

Live and learn.
 
#19 ·
Adding ammonia to a cycling tank without it will help, but water from a cycled tank should only have an almost unreadable amount of ammonia, so it's not worth it
 
#21 ·
Of course you can just purchase pure (aquarium safe) ammonia from a hardware store and put it in.. You'll have to work out how much to use. I believe putting in between 1-2ppm ammonia is good (?) Putting in a lot at once can ruin your cycle, however (?)
 
#22 ·
4 ppm is the perfect number. While higher, concentrated numbers will ruin and freeze your cycle. So ideally you shouldnt go anything above 4 ppm, as you will grow the wrong type of bacteria.
 
#23 ·
Ooook. So now the stupid question.

How do you know how much pure ammonia to add??? Sorry, I don't (yet!) speak PPM! I mean I understand the concept, but maths were never my strength.

Is there a dose/gallon I can use? Does the dose change based on where you are in the process????

The last time I did this I chucked in some food pellets and shots of water from the uncycled pet keeper I was using and I also used Cycle to help. I had a fairly plant filled tank though, so it was an awkward process and I occasionally got some screwy numbers on my water tests.

It only took about 2-2.5 weeks to cycle, but I finally achieved 0ppm on my ammonia & nitrites, and a low amount of nitrate.
 
#24 ·
I think it depends on the percentage the ammonia is.. That's all I can say because I have never used the ammonia. I am only cycling for the first time and I'm using the food method (except I'm putting it in a panty hose floating in the tank so I don't have this huge mess to clean).
That is a really fast cycling time from what I hear though. o-O
 
#28 ·
Gravel vacuuming is fine if your tank is use to it. If you never vacuum them do a very vigorous cleaning you could cause a mini cycle. If you gravel every week the bacteria will grow in other areas of the tank/filter to accomodate the bacteria that maybe lost during the vacuuming. Myself, I never vac my tanks. Most are pretty heavily planted. Fish poop = good fertilizer. If your tank needs vacuuming don't skimp on it. Gravel traps more junk then sand so will need cleaning more often.
 
#27 ·
Adding water from a cycled or a cycling tank will not help cycle a second tank. The amount of nitrifying bacteria in the water colum is minuscule. Removing 1/3 and in some cases 1/2 of the filter media from a stable, cycled tank to help cycle another will not throw the first tank back into a cycle. Once established the bacteria colony multiples fairly fast to accommodate the bioload of the tank. If you have a cycled tank and wish to start another there is no point (in my opinion) starting the cycle from scratch. Seeded media makes cycling very easy and quick.
If you don't want to remove gravel or filter media you can run the new filter on the established tank for 2 weeks to seed it with bacteria. Another option is to add extra media to the existing filter for 2 weeks then move it to the new filter in the new tank when you get the fish. This is what I do when a quarentine tank is needed. I run two filters on my goldfish tank and remove one to the new tank to instantly cycle it.
When ever moving filters and media from tanks you run a small risk of having a mini cycle where some ammonia and nitrite maybe present. If this happens a water change must be done daily until the bacteria multiply again.
 
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