Cycling Your New Aquarium
by: John Farrell Kuhns
Cycling a new aquarium is almost as easy as falling off the proverbial log. If you have had the luxery of planning ahead then you can actually "cycle" an aquarium in an hour or less. All that is required is that one have enough "cycled" gravel or other substrate to serve the needs of the new aquarium.
The cycled material is simply transferred to the new aquarium, the new water is added and properly conditioned, the plants and decorations are put into place, the filters are started (they should have already been set up) and once the water temperature is correct the fishes can be added. With this kind of "cycling" one can expect a very small, and most likely unmeasurable burp of ammonia, but it will quickly disappear and life will settle in quite nicely.
Most new aquarium set-ups, however, are not handled in this manner, and there is a logistical problem with handling all that extra gravel or other biological filtration substrate. In most situationsthe aquarist must go through a different process. This process, however, can be almost as simple and is relatively painless.
To begin; one sets up the aquarium. Puts in place the filtration (e.g. the outside power filter (e.g. a Marineland or Eheim brand cannister filter) with granular activated carbon (e.g. Marineland's brand) and an undergravel filter* (e.g. Perfecto brand) with the appropriate number of airlift tubes equipped with high-quality airstones (e.g. Mist-Air) and powered by a strong and reliable air pump). Add the rocks, diftwood and other decorations and then add the water. The filtration is started and properly tuned so that the water and air flow is proper. The heater, if one is to be used, is put in place and set. Next, treat the water with both NovAqua and AmQuel and "seed" the gravel bed with as much cycled gravel from an existing aquarium as possible**. Usually, only a quart of cycled gravel per 10 gallons of aquarium volume is needed, but even half that amount will eventually do the job. The next step is the most critical.
Add enough ammonium chloride, NH4Cl, (or ammonium sulfate, (NH4)2SO4) solution to the aquarium to bring the ammonia reading up to 1.0 mg/L (as NH3). Use a salicylate-type ammonia kit (the Aqua-Tru kits are superior to any other kit on the market) to measure the ammonia concentration. Some ammonia additives (e.g. Thiel-Aqua-Tek's Gold Start) actually are calibrated well enough so that following the directions on the bottle will result in the concentration of ammonia stated. Next, add enough AmQuel to bring the ammonia reading to -0- (as measured by the test kit).
This last step may seem counterproductive, but while the ammonia, as such, is removed from the water by the reaction with AmQuel, the nitrogen which was in the ammonia is still in solution as a different non-toxic compound. This compound is capable of being assimilated by the nitrite-producing bacteria just as if it was the unreacted ammonia. The next step, then, is the easiest; just sit back and monitor the water on a daily basis until the nitrite level drops to zero and the nitrate level starts to climb. Typically, the nitrite level will be much lower and will go away faster than is usual for cycling where AmQuel is not used. This is because ammonia inhibits the activities of the nitrate-producing bacteria.
These bacteria can't begin producing nitrate (and reducing the nitrite) until the ammonia concentration has dropped to nearly zero. With the use of AmQuel there is no ammonia in the water and the nitrate-producing bacteria can start oxidizing nitrite immediately (or, as soon as they are established). As soon as one detects the appearance of nitrate the pH and alkalinity of the water should be measured and suitable partial water changes can be made to bring up the pH and increase the alkalinity as needed. For all water changes the use of both NovAqua and AmQuel will help insure proper water conditions. This, then, is when the fishes can be added. This proceedure will usually reduce the cycling time by half or more.
Once the fishes are in place it is a good idea to monitor the water chemistry weekly for the first three months. Measuring the alkalinity will often give one a clue as to when to expect the water quality, especially the pH, to change drastically. In any case, pH, ammonia, and nitrite are always necessary to test when any problems occur.
*It needs to be noted that undergravel filters are easily cared for, and do not require regular cleaning or vacuuming as is often recommended by poorly informed aquarists. In reality, cleaning of bio-media is anathema to its proper functioning. The belief that gravel quickly becomes clogged is unfounded. In most aquarium set-ups the gravel bed over an undergravel filter plate will remain active for from 1 to 5 years. The appearance of low, persistent levels of ammonia and/or nitrite is the only viable way to establish that the undergravel filter bed (or any other biological filter) is not functioning properly. The use of rotating biological filters (Marineland's Bio-Wheel) is certainly viable and is a suitable replacement for a gravel filter bed. Given the fact that gravel is often desirable in an aquarium, then the installation of an undergravel filter, in addition to any other devices, is strongly recommended.
**Using gravel or other cycled substrate is usually preferable to any of the many enzyme and bacterial products being sold in the aquarium trade. Researchers have confirmed that most of these products are either unreliable or actually can slow the establishment of nitrification in aquariums. Some of the bacterial products may contain actual, viable bacteria or spores, but some or all of the species may be facultative rather than obligate nitrifiers. In addition, it has only recently been confirmed that the bacterial species thought to be responsible for nitrification in freshwater are not found in biological filters in freshwater aquariums. Facultative nitrifiers can, and will, change their preferred "food" source and can turn from nitrification to simple hetertrophy thereby reducing the overall nitrification. Heterotrophic bacteria also have shorter "doubling times" than nitrifying bacteria. This allows the hetertrophs to overgrow the substrates and prevent proper colonization by the autotrophic nitrifying bacteria. This is why some of these enzyme- and bacteria-products must be re-dosed at regular intervals.
The author invites you to post questions to him regarding this article or any other aquarium questions and to check out other information on the AquaScience Research Group's web site.
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