Can I use cycled filter media for instant fish in a new tank?

Hi and thanks for your request. To better control Nitrite and ammonia spikes it is best to cycle it for a month at least and measure nitrites, ammonia and nitrate constantly. Please follow the recommendations here below: The nitrogen cycle is the process of various bacteria converting harmful waste. It involves 4 steps: The first step is the decay of waste products of fish, plants, and invertebrates, along with any dead organisms or uneaten food. As these materials decay, ammonia is produced, which at even low levels will burn the gills of fish and choke off their oxygen supply. Bacteria called Nitrosomonas consume this ammonia and, in the process creating another chemical byproduct called nitrite. Although nitrite is toxic (preventing blood from carrying oxygen), fish can withstand roughly twice the amount of nitrite in their water when compared to ammonia. Next, other bacteria called Nitrobacter consume the nitrite and, in turn, release a less toxic chemical called nitrate. Nitrate requires anaerobic conditions to turn it into harmless nitrogen gas. The parameters needed to create this condition are not commonly present in most aquariums. Hence, water changes are necessary to dilute nitrate. The Nitrogen Cycle in New Aquariums Because new aquariums lack the colonies of bacteria that are necessary to provide biological filtration, the aquarium must be cycled. Cycling refers to the process of establishing and maturing the biological filter. Here's how it works: As the first fish in the new system begin to thrive, they produce ammonia. Without any Nitrosomonas colonies established to consume this toxin, levels climb and spike until the ammonia-loving bacteria population catches up. This phenomena can be observed by the naked eye as a sudden and temporary appearance of wispy, smoke-like cloudy aquarium water Ammonia levels then start to decline once the rate of ammonia production is less than the rate at which it is broken down by the bacteria. Nitrite goes through a very similar spike. Nitrite is produced through the biological activities of Nitrosomonas as they consume ammonia. As their numbers increase, so does the amount of nitrite, and in turn the population of nitrite-hungry Nitrobacter will begin booming from the abundance of nutrients. Nitrite levels will rise until the number of bacteria has increased to the point at which they break down the nitrite faster than it is being produced. The end product of this whole process is nitrate. Nitrate, in low concentrations, is not as toxic to fish and invertebrates, but can cause other problems in the aquarium. The best way to control nitrate is through regular partial water changes. Typically, new aquariums can be cycled in 2 to 6 weeks, but the actual length of time depends on many factors. Use a quality test kit to test your water conditions every other day, and when both ammonia and nitrite levels return to zero, you'll know the cycle is established.

Unless you submit a water sample for culture or microscopic exam, you won't be able to determine if there are beneficial bacteria. With ammonia at the current level, there are bacterial populations. It takes time and patience to cycle a tank, sometimes up to 6-8 weeks. I'm not a fan of the "boosters", since you don't know how long they have been on the shelf or if the biologics are even active. Sprinkle some flake food in the tank and allow nature to run its course. The bacteria will feed off the flakes and populate the tank. Perform a 10-15% water change using conditioned water as needed during cycling.

It is possible the tank has not cycled properly which results in high ammonia and nitrite levels which can kill fish. Allow the tank to run, without fish, for at least 4-6 weeks. During this time, use a home test kit or submit a water sample for testing every few days. The local Petco may do this for free or for a small fee. What you are looking for is to have ammonia and nitrites at 0 ppm and nitrates at 20ppm or less. pH can hover around 7 for most community fish. Avoid large, rapid swings in pH though. What is happening in the tank during this time is that beneficial bacteria are populating the gravel/substrate and the filter. These bacterial populations are responsible for the Nitrogen Cycle. This cycle breaks down wastes from fish, uneaten food and plant matter into by-products that are filtered out or dissipate. You can "cycle" a tank with fish, however this increases the risk of loss. Once your tank has cycled, you can add fish. You will still need to monitor water chemistry and perform partial water changes regularly. Use only conditioned water that is temperature matched to prevent stress or shock. You will also need to vacuum the gravel regularly and rinse the filter media. Never use tap water to rinse. Use a bit of tank water to protect bacterial populations in the sponge.

Ideally you would quarantine any new Fish in a separate aquarium for a few weeks to make sure they do not show any signs of diseases or infection. Once 2-3 weeks have passed without any signs of a problem then it is usually pretty safe to introduce to the common aquarium. Good luck and I hope they do well!

A fish tank will need a filter, a light/hood and a heater. Make sure the filter is rated for at least twice the tank volume. The heater should be adjustable since water temperature will depend on the species of fish. Good "starter" fish include Tetras, Mollies, Danios or Tetras. A new tank should be set up and left running empty for several weeks before adding fish. A pinch of flake food can be sprinkled in daily. This "cycling" will allow a population of beneficial bacteria to colonize the tank and filter. These bacteria will break down wastes (ammonia, nitrites and nitrates) which are toxic to fish.

Yes, you can rinse filter media (the sponge) using tank water. This will preserve beneficial bacterial populations in the sponge. The plastic filter parts can be rinsed and scrubbed using tap water. Perform a partial water change, no more than 30% total volume, using conditioned water that is temperature matched. To limit algae overgrowth, do not overfeed, limit lighting to 8-10 hours daily and monitor water temp. If possible, turn up filter flow to get the water moving. Algae thrives in slow moving water. Do this only if your fish are not affected by stronger currents.

Without anything to use for scale, it is hard for me to tell how big your tank is, but in general it seems very small. Also, the water that is in the tank appears very cloudy right now, so that would be the first place to start. Water quality is very important, and will make or break your ability to house and care for fish. I would recommend getting a good filter system (you can visit a local pet store to assist you with brands in your area, as I am not familiar with what you can get in India). Be sure to bring the measurements (height, length, width) of your tank, or the gallons or liters so they can tell you what capacity of filter you will need. Everything else will depend on what types of fish you get - if you plan on getting multiple fish, they will need to be small - a general rule of thumb is one square inch of fish per gallon of water. Depending on the species you get, you may need to also get a bubbler to ensure there is enough oxygen in the water for them, and you will also likely need to get some sort of substrate for the bottom and cage furniture (different species have different air requirements, and some are secretive and like to hide). You may also need a water heater, depending on the species you would like to house. But, depending on how small your tank is, it may be hard to get a water heater that will fit. The food type will also depend on what species you get, as there can be differences in diet type between species. I hope that gives you a place to start, and good luck!