what does it mean to "cycle" a fish tank?

Answer 1

Cycling refers to the nitrogen cycle. Fish produce ammonia in their waste, and this is toxic to them. In an aquarium, bacteria will convert the ammonia to nitrite (also toxic), then another group of bacteria convert the nitrite to nitrate, which is safe in moderate amounts. "Cycling", as it's used in fishkeeping is the period (3-6 weeks usually) when the bacteria is becoming established in a new tank, or one where the bacteria have been killed (by chlorine, antibiotics, or other chemicals).

Here are two links where you can get more in-depth information:

http://www.fishlore.com/NitrogenCycle.htm
http://www.firsttankguide.net/cycle.php

You may also hear about cycling as "New Tank Syndrome". This usually refers more to the cloudy water you get while the tank is cycling - the cloudiness is a "bacterial bloom" as the bacteria reproduce rapidly to take advantage of the excess ammonia and nitrite in the tank. Once there are enough bacteria to convert these completely to nitrate, the reproduction slows down, and the cloudiness will go away on its own. Many new tank owners see the cloudiness, and mistake it for dirty water, and tear down the tank and clean it - this only destroys the bacteria, so the process occurs all over again, and only prolongs the time that it takes (and that the tank stays cloudy).

Answer 2

1. A tank is determined overstocked by the size, mass, behavior, and waste output of the fish in it. Let's say you have a 10 gallon with 10 neon tetras. This is not considered overstocked because (a) each neon is 1 inch, (b) the mass of each fish is less than its length, (c) the fish are schooling fish, and (d) the waste output is minimal. Basically, 10 neon tetras have enough room in a 10 gallon to live happily and comfortably. Now take the same tank and put just 1 goldfish in it. Your tank is not overstocked with just the one fish. The reason is because (a) this fish get between 6-12 inches in length, (b) the mass is at least half as much as the size of the fish, (c) the waste output is greater than the mass of the tank. This means that the one goldfish will outgrow the tank (it will be bigger in inches than there are gallons). The fish's mass is just as large as the fish (meaning that the fish is as tall as it is long). Goldfish also produce a lot of waste. Their very messy fish. 2. There will be more waste and less oxygen the more fish you have in an overstocked tank. 3. You do a lot of water changes. I do mean a lot. It could mean anywhere from 2 times a week to every day, depending on the tank size and how overstocked it is. You should be doing 25% water changes every week anyway. 4. Yes. Overstocked means polluted water. Bad water quality equals bad health. That equals shorter life. 5. Yes. Gasping, clamped fins, fin rot, not eating, fungus, bacteria infections, ich, bloat, and many other things indicate a stressed fish. Basically, anything that isn't "normal". 6. Massive death of all fish.

Answer 3

The word "cycle" refers to the nitrogen cycle. ( http://www.aquahobby.com/articles/e_ciclo.php ) To sum it up: there's a type of bacteria that eats ammonia and produces nitrites as a waste product; another type of bacteria then eats the nitrites and produces nitrates as a waste product. This is important in a fishtank because fish waste turns into ammonia, but ammonia kills fish. Nitrates eventually will as well, but only in high quanitites. (That's why you have to partial water changes every week: to dilute the nitrates.)

To create it in your tank, you canNOT just let the filter run for 24 hrs. Even 24 yrs isn't enough if you're just letting the tank sit there and cycle clean water. The bacteria grow on a diet of ammonia. The more ammonia there is, the more bacteria grow. It won't grow just because you set up a fishtank and cross your fingers.

There are 2 ways to do it:

1) You can add some tough, inexpensive fish to the tank and let their wastes feed the bacteria. CONS: This can be a frustrating process, because the fish will get sick and even die from the effects of ammonia poisoning. The only way to lengthen their lives a bit is to do constant water changes. You could also just keep buying more fish until the cycle is done. This is a cruel and irresponsible way of cycling a tank. PROS: The only thing I can think of is that you can have fish in your tank from day one, rather than looking at an empty tank for a while. Of course, this assumes that you enjoy looking at fish while they suffer and die.

2) You can add ammonia to the tank without using fish. You can use fish food, prawns, or even just pure household ammonia. If you use that last, make VERY sure you use the pure stuff without any fragrances or soaps or any other chemicals that could kill your fish later. PROS: Fishless cycling is faster and more efficient than cycling with fish, since you can add plenty of ammonia right up front. Since you don't have to change the water, the bacteria grow more quickly on the high ammonia levels. The only labor on your part is to check the water levels periodically to see how the cycle is going. CONS: You have to be patient, you have to stay on top of the levels, and you have shell out the extra cash for the test kits. Of course, if you're not willing to do these things, your fish aren't going to live long no matter what you do because keeping fish alive and healthy requires being patient, keeping an eye on your water conditions, and having good maintenance habits.

*** NOTE: Using bacterial products like Cycle or Insta-whatever is a waste of money. They don't work. The only one that does is Biospira, and it can be a risk as well since it works because it's LIVE bacteria, and so it has to be religiously refrigerated right up until you use it or it starves off in the packet. It's easy to get a dud batch if anyone was even just a little careless during the shipping process.
*** 2nd NOTE: You CAN instantly cycle your tank if you have other healthy tanks already running or know someone who does, and can borrow filter sponges from them. Be careful when you do this. You have to take ENOUGH bacteria from the old tank to support the amount of fish you're going to put in the new tank. And you can't take too much from the old tank without throwing its cycle out of whack. Whenever you do this, you should keep an eye on the levels of both tanks for a while, just in case.

Here's an article that tells how to do the fishless cycle: http://www.aquahobby.com/articles/e_fishless.php Depending on the size of your tank, the recommended amount of ammonia in that article can be way too high. I think it's safer to add ammonia a teaspoon or so at a time and measure the levels as you go.

Good luck!!

Answer 4

Cycle Fish

Answer 5

Oh boy, be prepared for some serious scientific answers that still make my head spin after many years of keeping fish.

The short version is that your tank needs beneficial bacteria in it, which converts the ammonia produced by fish waste and uneaten food which rots in the tank.

If the ammonia and other naturally produced bad chemicals (like ammonia and nitrite) stay in the tank, they can kill your fish.

This takes time if it's done naturally.

To shortcut, buy some Stability or some other bottled or dried beneficial bacteria (called nitrifying bacteria - which is the bacteria that eats the bad stuff).

Another shortcut is to borrow a friend's sponge from their filter (assuming the tank is healthy) and put it into your tank.

Or, take some gravel from a healthy tank and put it into your tank.

It's all about getting enough beneficial bacteria in the tank to eat up the bad stuff - like ammonia.

I'm all for cheating. I keep extra sponges in my established tanks, so when I set up a new one - voilla! I put the sponge into the filter in my newly set-up tank and it's instantly "cycled" with enough beneficial bacteria to keep the nasty ammonia and other bad chemicals at bay.

So, don't believe folk that tell you you MUST keep the tank empty for a certain period of time. You can cheat with my methods above.

It's all about having enough good bacteria in there to take care of the waste. You can wait for them to grow on their own, or you can cheat by adding them from a bottle or established sponge, gravel, etc.

Answer 6

It's referring to the nitrogen cycle that tanks places in an aquarium. Nitrogen compounds build up from fish respiration, waste, excess food, and plant decay, in the form of ammonia. Bacteria strains, 2 different kinds build up. They break down (oxidize) these compounds into lesser harmful compounds. First ammonia begins to be broken down to nitrite, and then a couple weeks after the second bacteria grows, and takes the nitrite, and breaks that down into nitrate. Once you read 0 ammonia and nitrite in your tank, and only read nitrates, then your tank is cycled out.

This is very necessary to do before populating the tank with the fish you want to keep long term. Most fish cannot tolerate ammonia or nitrite in a tank and will die. Once you have the tank cycled, just add the fish you want to keep long term, a few at a time. Over adding fish after the tank is cycled will cause the tank to go through a mini cycle as the bacteria that is in the tank can only process the amount that it is used to. Additonal fish make more ammonia and thus cause bacteria to have to grow more. That's why you just add a few fish at a time to allow the tank to stay stable.

Answer 7

This Site Might Help You.

RE:
what does it mean to "cycle" a fish tank?

Answer 8

It's when you let all the tank components run, with or without fish, until beneficial bacteria start growing, and water chemicals become optimal to sustain fish.