Cycling

From ReefPedia

Contents 1 Introduction 2 The Case for Fishless Cycling 3 The Old Method 4 Fishless Cycling 5 Method One 6 Method Two 7 Method Three

Introduction

In the world of salt water aquaria and the first major component of starting a salt water tank, is it's cycle. Cycling is a complex bacterial absorption of one chemical element within the water column and changing it into a less toxic, new element. Some aquarist's refer to their tank as being cycled, but in reality the cycle has started and is something that is never ending.

Cycling is started by introducing either the original element or an item which will decay into the first element, Ammonia. Ammonia is the very first by-product of decay within the salt water environment and must be eliminated due to its toxicity to salt water inhabitants. Over time, bacteria will grow within the environment and water column, that will consume the Ammonia and convert it into a less toxic element, Nitrite. Nitrite is less toxic than Ammonia but is also toxic to salt water inhabitants. Given time, a new bacteria will develop to consume the Nitrites and will convert it into Nitrate. Nitrate is the least toxic element and the last element in the cycling process. Nitrate reduction is accomplished with regular water changes.

Once the initial startup of the cycling process has matured, all Ammonia and Nitrites will be broken down one by one into Nitrates. The matured cycle will show zero ammonia and zero nitrites but nitrates will continue to rise. The rising nitrates with zero of the other two elements is the indicator that the cycling is working within the water column. Once this condition of a matured cycle has been reached, your water column is now at equilibrium. Everything in the tank will contain the cycling bacteria; rocks, filters, bio media, and anything else that the water itself comes into contact with.

As your tank inhabitants increase, so must the consuming bacteria of the cycle. Fish excrete ammonia and adding too many fish at once will throw the water column out of equilibrium, because there has been no chance for the consuming bacterias to catch up. The bacteria will become overwhelmed and ammonia will rise causing a toxic environment for the inhabitants. It is always wise to take it slow when adding new live stock, so the cycling bacteria can catch up and keep ahead of the toxic elements being introduced by the new inhabitants.

The Case for Fishless Cycling

It has been a long standing practice to use some cheap fish to get this cycle going and keep them until there was enough bacteria to breakdown the Ammonia and Nitrite. It appeared and once this stage had been reached the aquarium was said to be mature and safe for other fish. Ammonia is extremely toxic to fish even when it is present in the tiniest imaginable amount, just one part ammonia in ten million parts of water is enough to cause stress, illness and even the actual death of some delicate species. Fortunately help is at hand in the form of some types of bacteria, these bacteria consume the ammonia as it is produced so there is never any free ammonia in the water once there are sufficient numbers of these helpful bacteria present.

The whole point of maturing or cycling the tank is to build up the numbers of these helpful bacteria so that there are sufficient numbers of them to cope with a tank full of fish. But this isn't the end of the process because these helpful bacteria which consume the ammonia have a big downside, they produce nitrite and nitrite is almost as deadly to fish as ammonia. But there is another species of bacteria which consume the nitrite and turn it into nitrate which is relatively harmless unless it reaches very high levels. Obviously this was a very unsatisfactory way to go about things because presumably anyone who set up an aquarium did so because they had an interest in fish and so it seemed ironic that the first thing you had to do to get started in this hobby was to kill or injure some fish.

The Old Method

The old method of maturing a fish tank was to place a few cheap fish in the tank after it had been set up and then let the ammonia build up when the fish excrete it. Once the ammonia was present the bacteria which consume it would begin to multiply and produce nitrite which in turn meant that the bacteria which consume the nitrite would begin to multiply. Unfortunately the levels of ammonia and nitrite levels would build up to such high levels that some of the fish would die and others would suffer from ill health both in the short term and in the long term.

Why subject something you like and something you have an interest in to the following?

• Ammonia

Causes fish to produce extra mucus over its gills, which means that they will work less effectively and leave the fish gasping to get enough oxygen, it also damages the small capillaries and they hemorrhage. The fish will also begin to twitch and swim erratically. Death will soon follow.

• Nitrite

Cause damage to the fishes hemoglobin and makes it unable to carry Oxygen the result of this is the fishes tissue dies and it develops deep ulcers and secondary infections again death soon follows.

Fishless Cycling

Method One

1. Set the new tank up with all its equipment, decorate it to your liking and fill it up. Switch the lights and filters on and leave it running as though there were fish in it.
2. After 48 hrs there may be a little cloudiness present in the water, this is entirely normal - do nothing. The cloudiness will disappear but it could take from a few hours to several days.
3. Once it has gone add some ammonia to the water - this can be in the form of unscented household ammonia or something which will produce it such as a piece of meat the size of a thumbnail. As the meat breaks down it will produce the required ammonia, but this method is more difficult to control. The household ammonia is preferable because it is cleaner to use and more easily controlled.
4. When using the ammonia solution add just 1 drop for every ten litres of water on alternate days. If the tank is a tropical tank set the temperature to 85F whilst the tank is cycling because the bacteria's metabolism will be around its peak at this temp and the cycling process will be speeded up as a result.
5. After about four days test the water for ammonia and nitrite. The results may or may not show any nitrite but keep testing two or three times per week until the nitrite level reaches 15 parts per million.
6. Once this target has been reached stop adding the ammonia and just wait.
7. A few days later the ammonia levels will have disappeared but the nitrite will probably hold steady for a time. The time it takes cannot be guessed at because there are to many variables which affect it. I have personally known it take from 11 days to 5 weeks and then out of the blue the nitrite begins to fall. Once it starts to fall it disappears quite rapidly, usually within hours
8. When it has disappeared without any trace return the temp to its normal level of about 76F and then the first fish can be added to the tank,
9. Don't add to many or what you have done so far will be wasted.
10. Add the first FEW fish i.e. 4 or 5 small fish.. The newly cycled tank won't be completely stable for the first few weeks so great care must be taken to keep the tank clean and not to over feed the fish.
11. After two weeks or so some more fish can be added and this is how you should proceed for the first 6 months of the tanks life.

Method Two

This is a much faster method if you have access to an already mature aquarium.

1. Set up the tank and equipment and run it as though there were fish already in it.
2. After 48 hrs take some filter media from the already established aquarium (about 1/3rd of the total) and add it to the new filter. Replace this media from the original mature filer with new media which will be colonized by bacteria very quickly.
3. 24 hrs later you can start adding the fish. Again this has to be done very gradually.
4. Adding water from a mature tank won't help in the slightest with the maturing process. It is a myth.

If you run a hospital tank or isolation tank from time to time you can place a small sponge filter at the rear of an established tank and keep it running there. This will ensure that it is always mature and ready for use at a moments notice so that a hospital tank could be set up and in use within minutes.

Method Three

This is a newer, more natural way to cycle a new tank. First, fill your tank, add your salt to get your specific gravity to the desired level. This should be between 1.021 and 1.025. Allow your tank to run as long as 2 days to be sure all your salt has dissolved, and all your pumps, powerheads, skimmers are working with no leaks. Purchase your live rock. Usually, 1-1/2 lbs per gallon of tank size is recommended. Put your rock in the tank. You will have to remove some tank water, as there will be some displacement with the new rock. You will have some die-off from the rock, and this will vary according to how long the rock has been in transit. You may brush the rock every couple of days to aid in cleaning. Arrange your powerheads in such a manner to blow over the rocks so they will get good flow over and around. Check your ammonia level after a few days, and you should see it rise. Be prepared to empty your protein skimmer frequently. Be sure to top your tank off with fresh water as necessary. You may or may not run your lights. At this point, it really doesn't help any of the photosynthetic organisms. Watch your ammonia, and when it begins to drop, test for nitrites. When your nitrites drop to zero, it's usually a good idea to do a major water change. Most of us hobbyists do not have the facilities to change 100+ gallons of salinated water at a time, so I do a 10 gallon change every 2 days for a week or so. After that, just 5% a week water change is plenty. At this time, your tank should be cycled. Check your nitrates, they should be <10ppm or less. You are ready for your next inhabitants!

   Original article contributed by Fish Tanks and Ponds

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