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You have made your decision as to the size of tank and type of set-up you want, and you have bought the tank, stand, lighting, and the other necessary pieces of equipment. The tank has been set up in its permanent location in the room, you have readied the filter, or filters, for operation, and you have placed the heater into the position you want it. If doing a planted tank, you have also added your selection of rinsed substrate, driftwood, or any other décor, and put your desired arrangement of plants in place in the substrate. As a last step before plugging in and starting the filters and the heater, you have filled the tank, at least to a 90 % level, with conditioned warm tap water of at least 82 F.
It is now important to ensure the tank is cycled. NEVER, never introduce discus to an uncycled, or cycling tank. It can, and probably will, kill them. It’s cruel and expensive ! ‘Cycling’ can probably best be described as the growth of colonies of beneficial types of bacteria, called nitrifying bacteria. They are necessary because they neutralize ammonia, convert it into nitrites, and finally render the nitrites to produce nitrates. Ammonia and nitrites are toxic to fish, whereas nitrates are much less toxic, and generally harmless in moderately low concentrations. When you cycle a tank, you are really cycling the filter materials, or media. While there will be some bacterial presence on the tank glass walls, on driftwood or other decor, and in and on substrate, a majority of the bacteria will likely be in the filter(s), although a good amount may be located in the substrate. Colonies of beneficial bacteria can only develop and survive in the presence of ammonia. In a cycled aquarium, these bacteria will maintain themselves in sufficient quantities to render harmless all the ammonia and nitrites that are being produced in the tank by fish waste, and by decaying plant matter, uneaten decaying fish food, etc.
Fresh water from the tap has very little or no ammonia and no beneficial bacteria. One of the more accepted methods of starting the cycling process, called the fishless method, is to begin introducing store-bought ammonia (NH3) to a newly water filled tank. Bottled ammonia is readily available in approximately 10% concentration with only water added. Read the label. It should contain only ammonia & water - no dyes, fragrances, nor surfactants. It should be colorless and should NOT produce any foam when shaken. You can buy this ammonia at most discount or chain grocery stores or hardware stores.
With the filter on and the heater running, add sufficient ammonia to your tank to produce an ammonia test reading of 4 or 5 ppm (parts per million). Start by adding one teaspoon of ammonia for every ten gallons of water, or five teaspoons in a 55 gallon tank. Swirl it around and let it sit. Please note that ammonia at the dosage level suggested above is the quantity needed when using a 10 % concentration of ammonia in water. If you’re using 100% pure ammonia, the dosage will need to be reduced accordingly, i.e., by 10 times, - only six to eight drops of ammonia per 10 gallons, since a teaspoon contains about 80 drops of liquid.
Test the ammonia level and add more ammonia if necessary, a half teaspoon or so at a time, until a test shows a reading of 4 or 5 ppm. Then test daily or every second day until the ammonia level has dropped to around 2 ppm. This indicates that bacteria have begun to develop and neutralize the ammonia. Test for nitrites at this point; you should get a reading indicating that nitrites are present. Add more ammonia, a teaspoon or two at a time, to bring the level back up to 4 or 5 ppm, in order to maintain sufficient ammonia in your tank for the growing bacterial colony to consume and survive. Keep testing for ammonia and nitrites daily, or every second day, while at the same time adding ammonia regularly until the nitrites have spiked up to a high reading. It will take a few more days for a high nitrite level to drop to a low range, as the type of nitrifying bacteria that renders nitrites into nitrates take somewhat longer to grow and multiply.
Over time, when your testing regularly reads a ‘0’ level for both ammonia and nitrites anywhere from 12 to 24 hours after you have added your last dose of ammonia, you will know that the bacteria levels have developed in sufficient quantity to deal with the ammonia in the tank. At this stage, the nitrates level will be high. Do a large water change of 75% to 90% to reduce the nitrates to 20 ppm or less. Your tank has now fully cycled and is ready for fish. Remember, you need to keep adding ammonia in small amounts every day or so while your tank is cycling and the bacteria colonies are growing, so the bacteria colonies will not die off, until you are ready to add fish to the tank.
This process can take from two to six weeks, but this method will usually accomplish it in around three weeks. This can be speeded up considerably if you add some colonized material from an established, mature and healthy tank, such as a small quantity of substrate placed in a tied-up nylon bag, or if you add a seasoned filter media, like a foam pad.
One final note, if you’ve opted to begin with a planted tank, consider allowing some further time following the cycle to acclimate and start your plants’ growth before introducing the discus. A total cycling and seasoning period of 45 to 60 days should allow the plants sufficient time to become established.
The entire cycling process can be eliminated if you can buy a cycled sponge from the discus supplier, or add a seasoned, colonized filter with all of its media intact from an established healthy tank to your new tank. In this case, fish can be added immediately. If you do so, test your water daily for the first few days to ensure there is no ammonia or nitrites. This is to confirm that the size of the bacterial colony you have introduced is sufficient to deal with the fish bio-load you have placed in your tank. If you add cycled media it should come from the fish supplier or from another tank you have, not another source like a friend or the LFS.




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