How to Cycle a Saltwater Tank in 24 Hours

Pic by Chris Favero on Flickr
Pic by Chris Favero on Flickr

How to Cycle a Saltwater Tank in 24 Hours


Cycling your saltwater tank can be deemed the most demanding task of setting up a new saltwater tank. This isn’t because the task itself is difficult.

Instead, cycling a saltwater tank usually takes an absurd amount of time.

Time that could be much better spent buying and adding fish to the tank!

How amazing would it be to have your tank set up, cycling, and filled with fish in under 24 hours?

Today, I’m going to show you how.

Tank Cycling Essentials

It’s Crucial to Work Diligently, Too

Whilst I am going to show you how to cycle your saltwater tank safely in less than a day, it’s also important to note to put careful work into the cycling process as well. 

Making the cycling process as speedy as can be may seem like a dream come true, however, if too quick to the punch, you can severely compromise the PH level of the tank, causing serious harm to the environment within. 

You likely won’t notice any visible disruptions, slight variations are unlikely to cause fish detectable distress, however, with the use of a tank testing kit, you may find that you are putting your fish at risk. 

The following methods have been proven tried-and-true by experienced tank owners.

What Is Nitrogen Cycling?

In short, the cycling process is the biological process that is crucial for a healthy tank. It is the purification of waste into ammonia. Healthy bacteria in your tank feeds on this ammonia, turning it into nitrite.

The Importance of Cycling

The cycling process removes harmful nitrites and ammonia from the water filter. 

This means when your fish make waste, it isn’t upcycled into the filter, and create a clog in the system or a poisonous environment for them. 

In addition, with a neutral PH, you’re keeping small amounts of these compounds for healthy bacteria to feed on, and not become a toxic environment to your fish. 

This process also regulates the systems nitrogen cycle: the conversion of nitrites to nitrates, giving your fish a happy and healthy home. 

If you’re uninterested in the method below of using an old filter, make sure that you are investing your money into a high-quality filter.

Live Rock

The Healthiest PH Level for Your Tank

Now that you understand how harmful an unhealthy PH level for your tank is, let’s break it down to a simple science what the ideal environment should look like for your tank. 

A healthy PH is a PH of 7. Get yourself a PH testing kit to see where you’re at. And remember, a bit of bacteria is needed for the right environment, so don’t be too worried about dipping a bit below. Always remember too, that the water filter should always be kept on and running. 

Switching the filter off deprives the healthy bacteria in the tank the essential oxygen that it needs to survive. At this point, it will take the oxygen from the water, as well as the fish.

It’s also important to note that you should be “micro-cleaning” your tank daily. This means removing any uneaten foods, visible waste, and overgrowth. 

Balancing the PH to a healthy level doesn’t take rocket science, either. If your test reads that the environment is too acidic, try adding a bit of baking soda to your tank to raise PH levels. 

If your test results deem the water to be too basic, the addition of some vinegar or lemon juice will stabilize PH again.

Simple Methods to Accelerate Cycling

  1. If you have access, try using an old filter from a different tank.
    In this way, the filter will already contain all the healthy bacteria that your tank needs. Nothing special is needed for this, simply place the old filter into your new tank.
  2. Add filter media from an old tank.
    With the addition of media—rocks and pebbles, substrates and other media, you are cultivating all the healthy bacteria needed for your new tank. With new products, it takes much longer for all these healthy bacteria to populate. Steer clear of loads of algae and other species of the like. They carry high levels of iodine, that in excess, could pose harm to your fish.
  3. Increase water temperature.
    Beneficial bacteria populate much faster in a warmer environment. Be careful not to increase it too high to be unsafe for your fish, somewhere between 71-79 degrees should work just fine.
  4. Use live bacteria.
    Yes! Live bacteria are sold bottled in most aquatic stores. These agents can make a significant difference in the time that it takes for your cycling process. Use immediately, so that the bacteria don’t die off and expire prematurely.
  5. Increase oxygen levels.
    This can be achieved with porous stones, and the addition of an air pump. You could also use a protein skimmer here, likely the cheapest method next to the air stones.

Cycling Bacteria

Hang-On Protein Skimmer

Containing Risk of Fish Deaths

Levels of ammonia in your tank must be kept maintained to minimize risk to your fish. Products such as Amquel can help keep ammonia contained in your tank. You could also do partial water changes periodically to achieve this as well.

You could also cycle your tank without the addition of fish at any point. The role that the fish play is by their own slow production of ammonia.

If having the fish in the tank isn’t of interest to you, chemical agents such as ammonium chloride can be used in supplement. Please note however, the use of chemical ammonia complicates the process a bit further because of the need to monitor water chemistry daily.

Since it is possible, if you are worried about the risk you may impose with having fish in your tank during cycle, consider the fishless cycle option.

Add 2-4ppm of ammonia to your tank for the first few days, and tiny amounts every 4-6 days to follow.

Though this method takes a bit more time and effort, you’ll rest assured that you’re not causing your fish any harm or distress, some being necessary to the initial stage of cycling. 


It’s certainly safe to say you can’t put any fish into an unsafe tank. Any of the methods listed above would provide ample certainty that you’re providing the proper PH to the environment, however, it is still highly recommended that you utilize a testing kit to be sure here.

Being sure that your tank has a good amount of healthy, live bacteria also provides for healthy reefing. It keeps unwanted pests at bay (quite literally) and prevents possible diseases that would pose threat to the health of your fish.

Enjoy the health of your new tank, and happy reefing!

Did you find this article helpful? Help Us & Share it.
Recent Posts