How Soon Can You Add Corals To A New Tank?

It can be very tempting to start adding corals to your new saltwater tank right away.

Everyone wants to have a colorful mix of corals in their tank as quickly as possible but this is not something that happens overnight.

Adding corals to a saltwater tank should not be rushed especially when the tank is new.

Remember this. 

Nothing good happens fast with a saltwater tank. Slow and steady wins the race. 

Corals can be very sensitive to water conditions and the parameters need to be within normal limits in order for them to stay healthy and colorful. 

When can you add corals to a new tank?

You can add your first coral when the tank has completed its cycle and the water parameters have been tested to be within limits.

The nitrogen cycle is when the beneficial bacteria begin to build up in your tank breaking down harmful ammonia into nitrite and then nitrate. 

Establishing the nitrogen cycle can take anywhere from 4-8 weeks.

Adding corals too soon can lead to the death of the coral which can lead to other problems in the tank.

Do corals need a cycled tank?

Yes, it is important to have a cycled tank prior to adding corals. 

If your tank has not completed its cycle yet, the water levels will be toxic and harmful for all livestock including corals.

Ammonia and nitrite levels will be high in a tank that has not cycled. The chance of your coral surviving in a tank that hasn’t completed its cycle is slim.

But not everyone will agree on this.

Some will say that corals do not need a cycled tank and they can be added to a new tank right away.

The reason being that corals do not have red blood cells and are not impacted by high levels of ammonia like fish and invertebrates are.

Here is what said when asked, How long should I cycle a reef tank before putting corals in?

You don’t. The short answer is that technically, there is no evidence that you need to cycle an aquarium before putting corals in.”


“But hey good news, corals don’t have blood, or red blood cells, and they don’t use hemoglobin to carry oxygen. So the most dangerous mechanism whereby ammonia harms our fish and higher inverts is not one which exists for corals in the first place!”

They also mention that corals produce much less ammonia than fish and consume nutrients which lowers the level of ammonia present in the water. 

In my opinion, why risk it? It’s always best to play it safe when adding corals into a new tank. It can be very stressful for the coral and it’s important to provide the best conditions possible to ensure the coral transitions into its new home successfully. 

Frogspawn coral added to a new tank

How do you know if your tank is cycled?

You will know your tank is cycled when the ammonia and nitrite levels reach 0. 

It’s important to use a good quality test kit to ensure accurate results. 

Proper water parameters for adding corals to a new tank

Before adding corals to a new tank, test your water parameters to ensure they are in the following range.

Temperature: 75-79F

Specific Gravity: 1.023-1.025

PH: 8.1-8.3

Ammonia (NH3): 0

Nitrite (NO2): 0

Nitrate (NO3): 1-5

water levels for saltwater tanks

How do you know if your tank is ready for new corals?

Other than testing the water parameters and ensuring your tank is cycled, there are a few other things to look for before adding new corals to your tank.

What types of fish/inverts are you keeping?

Not all fish are considered to be reef safe. There are many different types of saltwater fish that are ok to keep with corals but it’s important to research ahead of time to confirm that.

Some fish will pick at and eat corals causing stress and even death.

The same goes for invertebrates. Not all of them are safe to keep with corals. 

How much space do you have in your tank?

Keep in mind that all corals will grow and it doesn’t take long for some corals to outgrow their space in the tank.

If you don’t have plenty of room for the corals to expand, it’s not a good idea to put them in the tank.

Corals also need space in between each other as some corals are not compatible together and can easily sting one another.

Does your tank have the proper lighting and water movement available?

All corals require proper lighting and water flow in order to stay healthy. Not all corals are the same and they have specific demands.

Research ahead of time to ensure your tank can meet the demands of the coral. 

What are the easiest corals to add to a new tank?

If you have a new tank that has perhaps just finished its nitrogen cycle, there are certain corals that are easier to keep than others.

Some corals are more forgiving and can handle a new tank and other corals are very demanding and sensitive to water quality. Some corals can’t handle even minor changes. 

Here are some great coral choices to add to a new tank.

Soft corals

LPS corals

How much coral can I add at once?

There is no set rule for this as every tank will be different. 

Earlier I mentioned that nothing good happens fast in a saltwater tank. A good example of this is adding too many corals to the tank at the same time. 

Adding many corals at the same time can cause a variety of problems. Although corals do not produce the same amount of bioload as fish do, it’s still important to add coral slowly over time and monitor their health once in the tank. 

I suggest adding no more than 3 or 4 pieces of coral at the same time. If you are adding large colonies, reduce this to 2 or 3.

These numbers might be different for your tank but it’s a rule of thumb that I follow.  

It’s important to acclimate your corals and dip them properly to reduce stress. Corals will need time to adjust to your tank conditions and lighting which should be done slowly. 

can you have too many corals?

How long for new corals to open?

If you recently added a new coral into your tank, it may take some time for it to adjust and become comfortable.

Every coral is different and every tank is different so the amount of time it can take to open can vary quite a bit.

On average expect a coral to open anywhere from 2 or 3 hours to 2 or 3 days. It can even take up to a week for certain corals to begin opening. 

It’s also possible for the coral to start opening within the first few minutes.

There are so many variables involved to know exactly how long it can take.

You will need to be patient and monitor the coral for any signs of stress or illness.


Although you may be anxious and excited to add corals to a new tank, it’s important that you take your time and add them slowly over time as your tank matures.

Not only will this save you money if your coral dies, but adding them slowly will give you more options to adjust and plan for the long term.

Saltwater tanks always do better over time.

Related articles:

Can you use ocean water for saltwater tanks?

What corals eat Reef Roids?

5 Corals that can touch each other without getting stung

Acan coral care guide