# The Fishless Cycle



## Amie (Sep 15, 2010)

I am starting this so I will have a place to refer people with cycling questions. I am hoping to put all the information in it that I know and hope that it will be a complete reference. I'm also hoping that the rest of the hobbyists here will fill in my gaps to ensure it is complete.

For simplicity we are going to concentrate on the Fishless Cycle only. And, I would like to start by stating that a Cycle means it goes in a circle. This cycle is not about getting to the nitrates at the end but having more coming behind the nitrates when they are produced. 

The basic idea with this Cycle is to create the beneficial bacteria that keep your tank in check. Fish fecal matter, left over food and what fish breath out all become ammonia in your tank. Ammonia is poisonous to fish. We want to get rid of that ammonia in the tank before it kills the fish. How do you do that?? Well, you let it get eaten. There are bacteria that will eat the ammonia and then the ammonia will be gone. These bacteria, however, will cause nitrites to be produced. Nitrites are even more harmful to fish then the ammonia is. So, what do we do now? Well, the nitrites will get eaten too. But, what is left behind then is nitrates. In small amounts fish don't mind nitrates. To control the nitrate levels in a tank partial water changes are done. 

But, here is the most important thing people seem to forget when cycling: the cycle must continue!!!! In order to keep the nitrate levels up there must be nitrites and in order to keep the nitrites up there must be ammonia. What you want to have in your tank is a set up like this: ammonia is produced and nearly instantly turned into nitrites because there s a colony of bacteria there to do the job and then just as quickly converted to nitrates because there is a colony of bacteria there to do that job too. 

Bacteria are living organisms-if you don't feed them they will die. If you put too much ammonia in the tank then it takes the bacteria some time to catch up. That is why you should add fish to your tank very slowly. Ideally, would be maybe 1 every few weeks or so until you are finished adding them. That way your bacteria will always be keeping a close eye on the ammonia amount and will be able to keep up on it. 

Some common mistakes that people seem to make is that they put too many fish in too fast. I already explained why that is a problem. The other common problem I see is that they add a source of ammonia and then stop adding it and wait for the tank to 'finish' cycling. The tank does not finish. You are not trying to get to an end really. You are trying to make a circle. If you don't keep feeding the bacteria they will die.

Now, I am going to quickly explain how I do my fishless cycle. I have done this in 2 different tanks so far one 10gal and one 15gal and have not lost any fish out of the tanks since I did this:

I set up the tanks with water in them and the filter running and the heater going like I would if there were fish in the tank. Each and every day I added 1 flake of fish food to the tank. This is what creates the ammonia in my tank. And by adding 1 flake every day I ensured that as soon as the bacteria had finished breaking down one flake there was another flake right behind it for them to feed on. After a few weeks like this I started checking my water parameters. When the tests showed 0 ammonia 0 nitrites and very low nitrates I knew the cycle had finished. I waited another 4 or 5 days just to be sure before adding any fish and I still added my 1 flake per day. With a bigger tank I would recommend adding more flakes. I would go with a general rule of 1 flake per 10 gallons of water.

Don't change any media while cycling. Don't do water changes. Don't add chemicals. Just let nature take it's course.


----------



## beaslbob (May 29, 2009)

Oh really?


----------



## inspiritid (Nov 10, 2010)

I might add that you need to make sure that these nitrifying bacteria have a home that does not disappear. Generally, this means an area for bacteria-housing media in your filter -- an area that doesn't go away when you clean your filter or change your filter cartridge. For example, a biowheel, a sponge that you rinse out in tank water only, a package of porous materials designed to house bacteria (there are many available), etc. 

Note that it could be argued that if you have a tank with a porous substrate and lots of plants, the contents of your filter become far less important.


----------



## jrman83 (Jul 9, 2010)

I prefer finding a source for liquid ammonia and applying it that way.

Your gravel or substrate will house a lot of your beneficial bacteria also.


----------



## Amie (Sep 15, 2010)

inspiritid said:


> I might add that you need to make sure that these nitrifying bacteria have a home that does not disappear. Generally, this means an area for bacteria-housing media in your filter -- an area that doesn't go away when you clean your filter or change your filter cartridge. For example, a biowheel, a sponge that you rinse out in tank water only, a package of porous materials designed to house bacteria (there are many available), etc.
> 
> Note that it could be argued that if you have a tank with a porous substrate and lots of plants, the contents of your filter become far less important.


Right on!!
But these bacteria will get everywhere so the tank is good as long as you don`t do a bunch of things at the same time. If you have more then one media in your filter don`t change them bot at the same time. Don`t clean your gravel within a week of changing some of the media. There are always going to be little things that send the tank into a mini cycle but as long as it is only a mini mini cycle then the fish will with stand it.


----------



## PolymerTim (Sep 22, 2009)

Amie said:


> Right on!!
> But these bacteria will get everywhere so the tank is good as long as you don`t do a bunch of things at the same time. If you have more then one media in your filter don`t change them bot at the same time. Don`t clean your gravel within a week of changing some of the media. There are always going to be little things that send the tank into a mini cycle but as long as it is only a mini mini cycle then the fish will with stand it.


The bacteria actually secrete a glue-like substance that will keep them adhered very strongly to your substrate. A typical gravel vac will not pull them off.

I also used the liquid ammonia approach with great success. With it, I was able to build up a bacterial colony much larger than I would have needed for a fully stocked tank, but being my first tank, I only put in 6 gold barbs (29 gal FW). I tested regularly and never saw the first hint of ammonia or nitrites since. But you do have to keep adding the ammonia. Unlike adding fish food, when your ammonia is eaten up, that's it. With fish food, it will continue to decay over time and produce more ammonia for a while. I will also note that, because of the large amount of ammonia added during my cycling, I had to do a couple large (90%) water changes to get my nitrates below 40ppm before adding my first fish.


----------



## snail (Aug 6, 2010)

Thanks for taking the time to write this. You've explained it in an easy to grasp way. In time most people develop their own preferred method of cycling and when it comes down to it they all work but some one new to the idea just needs to start with a basic understanding and I think this will help.


----------



## Amie (Sep 15, 2010)

Actually, come to think of it though, when my tanks cycled and before I added fish I did not do a water change. The nitrates level was low so I just left it alone.


----------



## PolymerTim (Sep 22, 2009)

Amie said:


> Actually, come to think of it though, when my tanks cycled and before I added fish I did not do a water change. The nitrates level was low so I just left it alone.


That should be fine as long as your water chemistry looks good. I think the main difference is that I was adding ammonia directly and you were adding it indirectly via fish flakes. It took quite a while for my second colony of bacteria (the ones that turn nitrites into nitrates) took hold and I added a lot of ammonia during that ~5-6 weeks before the tank finally cycled. When it finally went, it turned off-the-chart nitrites into off-the chart nitrates literally overnight.

But one nice thing about the direct ammonia addition is that it is easy to build up the size of your colony by the amount of ammonia you add.


----------



## Amie (Sep 15, 2010)

Absolutely agree. So, potentially you could create enough bacteria in a 55gal so that the next day you could go and fully stock it without problem. But, I think I'd still really air on the side of caution though. The thing I don't like with the ammonia (and I have not tried cycling with it myself) is that according to the posts I've seen here you should add it until you have a certain amount of ammonia showing up on your test kit. That sounds like a pain in the butt to me. Add ammonia then test the water to see if the level is where I want it then add more etc etc. This one just struck me as so much easier: 1 flake per day-that's it. Potentially though-I guess if you added more flakes in a smaller tank per day then you could build a big enough colony then like with the ammonia.......

Maybe next tank I will have to bite the bullet and go the pure ammonia route.


----------



## jrman83 (Jul 9, 2010)

For ammonia, you only have to add-test, add-test the first day. You record the amount and then add that everyday.


----------



## Amie (Sep 15, 2010)

That makes it sound a little better. I think some people mess up their cycle with that one too-they don't add more pure ammonia after the first day.


----------



## PolymerTim (Sep 22, 2009)

Sorry to come back so much later for a post, but just remembered this thread when you linked to it from another.

I don't think it's necessary to continue adding ammonia daily at the beginning. You only do that once the first bacteria grow and ammonia levels start dropping. I started with a general recommendation of how many gallons per teaspoon (for me, it ended up being ~1 tsp per 10 gal, but store bought ammonia concentrations vary). My first shot didn't get me to the 3-4 ppm level, but it did put me on the charts, so simple ratio math got me there on the third try (I was a bit too conservative on the second attempt).

After that, I just did ammonia checks every couple days for about a week when I saw my first bacterial colony getting hungry. After that, I fed them ammonia twice daily. Each time I would get the level to 4ppm and it would be below 1 ppm 12 hours later.

Of course, then it took a whopping 7 more weeks to get my second bacterial colony, but I think I now know where I went wrong there. It's a long story I'll have to post sometime.


----------



## Amie (Sep 15, 2010)

I got mine finished in about 3 weeks with no hiccups so I figured Id try to keep it as simple as possible. It probably would be fine to just do it every few days or so but if it aint broke dont fix it LOL


----------



## Frank1971 (Aug 23, 2010)

What if I added water conditioner already? Does that affect the cycle?


----------



## jrman83 (Jul 9, 2010)

Frank1971 said:


> What if I added water conditioner already? Does that affect the cycle?


You need to. Chlorine/chloramines will kill the beneficial bactria you are trying to grow.


----------



## Gizmo (Dec 6, 2010)

Another way to lower nitrates in your tank is with a lot of plants. Plants love nitrates, and they love nitrite and ammonia even better (breaks down to nitrogen easier).

A great way to be able to have a higher capacity for fish in your tank is with the aforementioned plant host, and a small army of shrimp or other equally effective cleanup crew. The shrimp will consume as much of the decomposing fish waste (and other things like algae and dead plant matter) before it generates too much ammonia.

If you play your cards right, as in a beaslbob build, you might feasibly be able to get away with zero water changes. This takes some very expert aquarium-designing ability however, in my opinion. It has taken me years to build my tank to the point that it is relatively self-sustaining, and I still do my PWC's out of habit.


----------



## mrouse (Feb 21, 2011)

During the cycle time, if the tank has terrible terrible green water!!! terrible, can a uv sterilizer be used for the green water? Would this affect the cycle? Obviously I did this, fish are happy and healthy, everything seems good, ammonia. nitrites, nitrates are right about right.


----------



## jrman83 (Jul 9, 2010)

Yes, a UV can work. The easiest to do is a total blackout for 2-3 days. No light, no feeding, and put a blanket over the tank. Algae in the water needs light and it will die. Ambient light will keep it alive, so do cover it. Is the tank near a window where it gets direct light?


----------



## mrouse (Feb 21, 2011)

It is about 8 feet away from a window, but I try to keep the blinds closed during the day. 
My water is looking really good right now, fingers crossed.
Thanks


----------



## Tropical Tina (Mar 13, 2011)

This is how I'm cycling my 48 gallon and so far so good. I also did my ten gallon this way. It is easy and works! Thank you.


----------

