Published on Wednesday, 28 May 2014 05:48

There are two common ways to cycle a tank and a third which is a little less common. Fish cycle is often done by beginners. Fishless cycle is by far the best option out there. Silent cycle is more for advanced plant keepers. All three have their advantages and disadvantages. Though before we start one major thing to understand is what is cycling.

At its very basic cycling is the growth of good bacteria that leads to supporting life in the aquarium. Without getting to technical there is several kinds of bacteria in the water. One kind of bacteria uses up or eats ammonia that the fish produce though waste. Their by product is nitrite which a second bacteria uses up or eats. These turn into nitrates. So to go over again ammonia – nitrite and nitrates. When cycling a tank you should have a test kit. Api makes a good master kit which you can get for under $20. This will test ph along with ammonia nitrite and nitrates.

Here are a few basics that will put you ahead of most others. While this whole bacteria thing sounds completed it really isn’t that bad. Many people start to understand the basics but not the complete picture. Many think once a tank is cycled you can just toss in a whole tank of fish. It’s best to start slowly and add new fish every couple weeks if you can. The typical suggestion is to only add 50% or less of the bio load at a time. For example you start with 10 neon tetras and in two weeks or so it’s safe to add 5 more. Bigger fish have a higher bio load meaning they produce more waste. When a tank is fully cycled there is just enough bacteria to support the fish in the tank. Removing fish there will be a die off of bacteria while adding more fish will increase the bacteria number. Again this has to do with the bio load. Another common misunderstanding is that bacteria is only in the filter. While a lot of the bacteria is in the filter it’s also on the décor substrate glass and even in the water. There is a very minimal amount of bacteria in the water though. Since most of the bacteria is in the filter this is why it’s best to always run two filters in case one dies or when you clean one you done wipe out the bacteria colony. You now know more than many fish keepers out there.

Fish cycle

Fish cycle is by far the most common used by beginners. It can be stressful for you and the fish. Often in many cases it can lead to death of fish or at least shorten their life span.  Most people buy a tank fill it up and toss fish in. as they die off they replace them but sooner or later the tank is cycled. In the meantime the fish could have been injured from ammonia burn.

Even though I don’t suggest it fish cycle can be done properly. It will normally take 8-10 weeks which is longer than a fishless cycle. It requires a lot of water changes and a lot of testing which personally I don’t find fun. I got into fish keeping to enjoy the fish not run a bunch of tests. You will want to start with a minimal amount of fish. Depending on tank size and fish size you will want to start with 5-7 fish.  During this time you should test every other day until ammonia starts showing. Once ammonia starts showing up it should be tested daily.  Any time the ammonia or nitrite hits .25 or above do a 50% or larger water change. Ammonia or nitrites above .25ppm can be very harmful to the fish. Even the .25 ppm isn’t ideal and can cause issues. You will see the ammonia spiking after a few days. In a couple weeks you should start seeing nitrites on your test kit. A couple weeks after that nitrates should start popping up. A tank is fully cycled with the ammonia and nitrites read 0 ppm and you have nitrates in the water. This takes longer then fishless cycle because you keep the ammonia levels down.

Fishless cycle

Fishless cycle is by far the best way to cycle a tank. It normally take 4-6 weeks. For the most part no water changes is needed for this. The first step is to get pure ammonia. You want the non-scented 100% pure ammonia. Slowly add the ammonia and test until you get to 3-4 ppm. I prefer to stick to 3ppm. Too much ammonia can kill off the bacteria. If you add too much just drain and start over. Every couple days you should test the water. As the ammonia starts to be converted into nitrites you will need to add more ammonia. You will want to maintain a 2-3ppm ammonia level in the tank. I know this can be hard having an empty tank just sit there just remember it’s for the good of the fish. The tank will be fully cycled when you can bring the ammonia up to 2ppm-3ppm and within 24 hours the ammonia and nitrites levels drop down to 0.

Silent cycle

Silent cycle is less common than the others. The idea is pack the tank with a lot of fast growing plants with a minimal amount of fish. The plants will grow using up all the ammonia. If not done correctly the ammonia will spike.  Once cycled you slowly add more fish.  Floaters are very good for silent cycle since they tend to grow the fastest.

Speeding up the cycle

There are several ways to cut down on the cycle time. There are several products out there that help some like tetra safe start or DrTim’s Aquatics One & Only Live Nitrifying Bacteria. Dr tim is the leading researcher and developer in the field. He came up with safe start and later started his own company offering a newer better product. If you want to save yourself some money there are other options to choice from. Remember the bacteria lives on the décor substrate and filter media. A handful of substrate from a cycled tank can help cut the cycle time by 1-2 weeks. You can also use some of the media from a cycled tank to boost as well will often cut the time by 2 weeks sometimes even more.  Just remember to make sure it’s coming from a safe and disease free source.  Many times a local fish store will give you some media or substrate if asked. Other options are finding someone with a local aquarium. Fish clubs, fish forums and even facebook are helpful with this.

As you get more and more tanks you end up having enough bacteria on the media you can just pull from several tanks. This is what is often called an instant cycle. You can practically just set up a new tank with a filter with media from the cycled tanks and be safe to go. Though this is for the more advanced fish keeper. Any time you set up a tank you should always keep up with the tests to make sure there isn’t any spikes.