Despite what many amateur hobbyists may think, a quarantine tank is an essential part of fish keeping.
It has many uses and can help improve your fish’s health and prevent sudden diseases and deaths.
Some fish keepers may not want to cycle the tank, mainly because it takes time.
Continue reading to understand the importance of having a quarantine tank and learn easy methods to cycle it.
Does a Quarantine Tank Need to Be Cycled?
A quarantine tank isn’t that different from your main tank.
If the water isn’t appropriately cycled, toxic waste and chemicals will build up quickly and put the well-being of its inhabitants in danger.
Therefore, neglecting to cycle the tank is out of the question.
It’s the method of cycling that can vary depending on the purpose of the quarantine tank.
For a permanent quarantine tank, you can add a source of ammonia to the water so that beneficial bacteria can feed on it and develop a colony.
Keeping a filter sponge in your main tank’s sump can help you in an emergency.
Just put the cycled sponge in the quarantine tank that’s filled with water from the main tank.
You won’t need beneficial bacteria in a hospital tank because the medication will kill them.
You’ll have to cycle the tank by performing 100% water changes.
What’s the Cycling Process?
To better understand why you need to cycle your quarantine or hospital tank, you should first understand the nitrogen cycle.
When fish breathe, they produce a toxic chemical called ammonia through their gills.
Their urine and fecal matter build up in the tank and decay, producing more ammonia.
Any organic matter like dried plant leaves, corpses, or leftover food bits will also decay in the water and leach out ammonia.
Even if there’s 1.0 ppm of ammonia in the water, the fish will suffer multiple problems which can eventually lead to their deaths.
There are beneficial bacteria (Nitrosomonas Bacteria) that feed on ammonia in a cycled aquarium and turn it into nitrites, also a toxic chemical.
Other beneficial bacteria (Nitrospira Bacteria) consume nitrites and emit nitrates, which is a less harmful compound.
This process is called the Nitrogen Cycle or Nitrification.
Now, how do we get these bacteria in our newly set up tanks?
Fortunately, these bacteria start growing on their own if they have their food source: ammonia and nitrites.
However, they may need time to multiply and create a large enough colony to support the fish waste.
It may be a month or more before the bacteria can attach themselves to the filter media, substrate, decorations, or driftwood and cause the ammonia levels to drop.
You can fuel their growth by introducing a piece of surface area that the bacteria can live on.
It can come from an established aquarium to jumpstart the population.
What’s the Purpose Behind Cycling?
Aside from containing poisonous chemicals that can hurt your livestock, a tank that’s not well-cycled doesn’t provide a stable living environment for its inhabitants.
The water parameters will fluctuate, causing stress and diseases for the fish, corals, and invertebrates.
A well-cycled tank means you’ll have healthy and attractive fish and corals for a very long time.
Why You Shouldn’t Let a Fish Go Through Cycling
If ammonia builds up in the tank, it’ll poison the fish.
They’ll experience respiratory distress and breathing problems.
Plus, red spots will appear on their skin, and they’ll have internal or external bleeding.
If the problem persists, the toxins will start to damage their nervous system, and they’ll go through hyperactivity and erratic swimming.
You’ll see a white clouding on their bodies because of mucus hyper-production.
They’ll even attempt to jump out of the tank.
Nitrites can also hurt the fish by binding with their blood, preventing the oxygen from doing so.
This can cause lethargy, tissue damage, secondary bacterial or fungal infections, and brown streaks in the tail and fins.
If you leave these issues untreated, you’ll soon witness a chain of deaths in your aquarium.
Why You Need a Quarantine Tank
The most common use for a quarantine tank is for a newly purchased fish, coral, or even plant.
New fish could carry infectious diseases, bacteria, or parasites.
You won’t recognize a sick fish at first.
Therefore, if you put it directly into your main tank, it may transfer diseases to other fish.
Parasites and bacteria have a certain life span and only manifest in a particular stage of their lives.
Corals and marine plants could bring unwanted eggs or hitchhikers to your tank.
Some of them could be beneficial for the ecosystem, like amphipods and copepods.
However, others could cause diseases or multiply fast and overrun your tank, such as some snails.
This is why you need to keep a new fish, invertebrate, or plant in a quarantine tank for at least 20 days before transferring it to the main tank.
In this period, if you realize your fish is sick, you should start treating it with medication.
Most effective fish medicines contain copper, which is very harmful to invertebrates like corals and shrimps.
The medicines could also harm and kill the beneficial bacteria population and collapse a nitrogen cycle.
That’s why you could use a quarantine tank as a hospital tank to treat new fish or the fish that get sick or injured in the main tank.
New fish usually experience a great deal of stress when you transport them to your home.
The stress can make them prone to many diseases, which is why it’s better to let them relax in a fish-less environment first.
Your new fish may be wild caught, meaning it’s not used to eating commercial fish food.
Keeping them in a quarantine tank can help them get used to the food.
This way, they can compete with other fish when it’s feeding time.
A quarantine tank is a great place to divide up aggressive or territorial fish that attack each other.
You can also use it as a breeding tank or put the pregnant females in it until they lay their eggs.
Cycling a Quarantine Tank
1. Permanent Cycling
If you’re planning to keep your quarantine tank permanently, this is the best choice for you.
This method will take some time and effort, but you’ll get the best and safest results.
The water parameters will be stable and close to the main tank’s conditions.
You’ll need to set up your tank first.
Add a power or canister filter and install the filter media, which acts as the surface area for the bacteria to grow on.
Fill the tank with dechlorinated water, or else the chlorine won’t let the bacteria populate.
Now you need to add a source of ammonia to the water for the bacteria to feast on.
Once the ammonia levels rise, the bacteria will jumpstart the cycle.
After a week or two, the nitrite levels will start to increase.
You need to keep dosing the tank with ammonia.
Test the water parameters every couple of days to make sure the ammonia level doesn’t exceed 5 ppm because it can kill the nitrifying bacteria and delay the cycle.
Once the nitrate levels start to rise, the ammonia and nitrite will fall to 0 ppm.
At this stage, you’ll have to do a significant water change to bring down the nitrate levels, and your tank will be ready to house fish and invertebrates.
Here are a couple of ways to provide ammonia for the beneficial bacteria:
- Food Particles: Add some fish food to the tank, and it’ll start to decay since nothing’s in there to eat it. The decaying matter will then release ammonia into the water. Test the ammonia every few days and add some food if it’s still under 3 ppm.
- Shrimp in a Mesh Bag: This method works the same as above. You should put a piece of cooked or raw shrimp into a mesh bag or pop sock and submerge it in the water. The decaying meat will fuel the ammonia. The mesh bag prevents the rotten bits from floating in the water and polluting the tank.
- Dosing with Ammonia: Adding ammonia directly to the tank will help you skip the first stage. Purchase household ammonia, dilute it with water and add the mixture to the tank. You should have a reading of 3 to 5 ppm on the test kit. Check the levels every day, and if they’ve dropped to under 3 ppm, dose the tank again.
- Snails: Some snails are highly sensitive to ammonia, but others are hardy creatures and can survive a cycle. Pest snails are pretty indestructible, and they can produce enough waste to leach ammonia. Even if they die during the process, their decaying bodies could fuel the ammonia levels. After using the quarantine tank, you can put some starter fish like gobies or some shrimps and snails inside to keep it cycled.
2. Emergency Cycling
If you don’t have the space, time, or energy to keep the quarantine tank running, you can use the emergency method.
You’ll need to plan ahead for this to work, though!
Keep an extra sponge filter in your main tank’s sump.
This way, it’ll be a mature filter that houses a colony of beneficial bacteria.
Set up the equipment and fill 75% of the quarantine tank with the main tank water and the rest with dechlorinated water.
Add the sponge filter to the tank, and there you have it: A cycled tank!
After your work is over with the quarantine tank, wash the tank and sponge with a diluted bleach solution.
Dry out the sponge and put it back in the sump again for later use.
3. Hospital Tank Cycling
If you’re dealing with sick fish and need to use medication that hurt the beneficial bacteria, having them in the tank is pointless.
To prevent ammonia from building up, you’ll have to test the levels every day and do 100% water changes once they rise.
Then, dose the tank with salt and medication again.
Once you move the healthy fish to the main tank, clean the tank thoroughly to prevent infections from transferring to your next guests.