For all the aquarists out there, the most exciting part of setting up a new tank is adding the fish. But you have to be careful here. It is very important to introduce the right fish at the right time. Because the health of the fish depends a lot on how and when you put them in a new tank.

It usually takes several weeks before you can start adding fish to a new reef tank. Because even after you are done setting up your tank, there are still some things to do to prepare your tank for adding fish. They are mostly about the water, building the tank foundation, arranging a lighting system, etc.

Every step has to be done in time and with care as they directly involve the wellbeing of your fish. I am going to make an elaborate discussion for each of the steps so that you can do it right. Keep reading, okay?

How To Add Fish To A Reef Tank: Stocking Guide

How To Add Fish To A Reef Tank: Stocking Guide

Adding fish to a reef tank for the first time is not simple. You’ll have to ensure a lot of things before even thinking about adding fish. Here are the steps you need to follow:

Step 1: What To Do With The Tank Water?

When you prepare the saltwater for your tank, fill it with the water. Then, install the aquarium heater and set the optimum temperature. Leave it like that for some days. Have it run for a week or so that all the equipment can function properly and the water temperature becomes constant.

Step 2: How Do You Build The Tank Foundation?

After your tank has run successfully for several days, start working on building the tank foundation by using live rock and aragonite-based substrate.

You can also try using 2 or 3 inches of live sand. It will seed the sand bed with beneficial microorganisms and bacteria.

After you are done adding the substrate and the live sand, bring the live rock. Be very sure that the live rock is properly cured. It will provide your tank inhabitants with safe hiding spaces, harbor beneficial microorganisms & bacteria, and help to maintain the water parameters. While working as a biological filtration system, it will also contribute to the aesthetical appeal of your tank.

You can choose any type of live rock. But you have to determine the amount of live rock first. It is a general rule that for each gallon of water, around 1 to 1.75 pounds of live rock are required. Note that the amount will vary with the type of live rock you choose.

As already mentioned, the live rock has to be fully cured before you add any fish to your reef tank. The curing process initiates the nitrogen cycle and it usually takes 4 to 5 weeks. During this time, you have to make 25% water changes weekly.

To cure the live rock, stack it loosely in your tank. Build as many caves as you can. It will allow your fish to swim freely and ensure good water circulation.

Remember to turn the most colorful side of the rock upward. It will provide proper lighting for the colorful coralline algae that require bright light and provide low light for the sponges which they require to survive and grow.

You must keep your tank dark during the process so that the algae can grow. Use light only when you have to check the tank for progress.

Step 3: Any Precaution To Take Before Adding The Fish?

When the live rock is fully cured and the biological filtration becomes mature, it is time for you to start adding fish to your tank.

But before you start doing so, there is a precaution you should take – test the levels of nitrate and ammonia in the tank water to make sure that their levels are 0 PPM. Then, set up a lighting system and use a timer to keep it illuminated for 10 to 12 hours a day.

In the following few weeks, you will notice an algae bloom. To keep it under control, use an algae attack pack in your tank.

Follow the procedure of acclimation explained in the pack and let your tank’s biological filtration handle the algae bloom. Because of the live rock, the biological filtration will take less time to accommodate the fish you are planning to add.

Afterward, wait a few days more for the nitrate and ammonia levels to become zero. And then, finally, get prepared to add fish to your tank.

Step 4: How To Add The Fish Now?

Now that your tank is all ready for adding fish, you can start putting the fish in it. But please be aware if there is any compatibility issue that your chosen species may have. And be sure that you take time to add fish so that the tank can let the biological filtration adjust to the new biological stock.

While you plan the initial and additional orders of adding new fish, check the nitrate and ammonia levels first and ensure that their levels reach zero and remain constantly at zero. Once that is confirmed, you can add new fish.

The first bunch of fish that you add to your tank must be the most gentle and docile of all the fish you are planning to keep in the tank. It will let them adjust to the environment of the tank before you introduce any larger and more aggressive fish.

Give the first ones at least 3-4 weeks. After that, gradually add the larger ones.

You may wonder how many fish you can keep in your reef tank without any trouble. Well, it depends on a number of variables. But the general rule is that you can stock no more than half an inch of fully grown fish for each gallon of water.

For instance, if your tank has 30 gallons of water, your ideal amount of stock is no more than a total of 15 inches of fish that are fully grown. While calculating the amount, remember to consider the maximum size of the fish you would like to have in your tank.

Step 5: How To Maintain The Water Parameters?

After you have added the fish, it is important to maintain the water parameters because if they are not stable, the water quality will fall and the fish will become stressed.

In order to keep the water quality stable, you should add a detritus attack pack. The invertebrates in the pack feed on the leftover food and waste from the fish. Choose a pack that suits the size of your tank and it will do the rest of the work.

What Are The Mistakes You Can Do During The Process?

There are some common mistakes that beginners usually do during the process of adding fish. If you know about them beforehand, it will save you from a lot of unwanted troubles. So, here goes the list!

1. Starting With A Tiny Tank

Tiny tanks are cute, I will give you that. But believe me, if you are a beginner, they won’t be a good choice for you because the volume of water is small in a tiny tank. And so, the water parameters change very quickly and they give you no chance to make mistakes.

So, beginners should choose tanks above 20 gallons until they have enough experience. Before then, a big tank is the right choice. The bigger your reef tank is, the less impact your mistakes will have on your tank inhabitants.

2. Adding Fish Too Soon

It is normal that tank owners, especially the new ones, are very eager to add fish when they set up their tanks. But the problem is they often cannot wait long and end up adding fish on the same day they have set up their tanks. This will soon result in the deaths of the fish if they are not too lucky.

The water of a tank has to stabilize before accommodating fish. There are many gases and chemicals dissolved in the water that can harm the tank inhabitants. So, it has to be treated to neutralize the harmful materials and allowed to be kept for at least a day so that the dissolved gases can escape and the pH level becomes stable.

It will also take you a day to ensure that the filtration system is functioning properly and the heater has brought the tank water to the correct temperature and there is no leakage in the tank.

When all of this is confirmed, you can be sure that it is safe to add some fish to the tank. So, do not add fish too soon. Be patient or it will all be for nothing!

3. Keeping Fish That Are Not Compatible

A lot of hobbyists choose fish that they like without knowing their characteristics and environmental needs. This results in a hostile environment inside the tank where the incompatible fish may fight with each other. Some of them may require different water conditions.

This is a common mistake that can lead to many troubles. But a thorough research can help you prevent this kind of situation. Always do some research on the species before choosing them as your tank inhabitants. Choose some peaceful fish that will thrive in similar water conditions.

4. Overstocking The Reef Tank

Another common mistake for new tank owners is to overload their tanks with fish. An experienced aquarist may keep 20 small fish in a 10-gallon tank. But it would be nothing short of a failed attempt for a beginner.

If you are a beginner, add the ideal number of fish until you gain enough experience.

5. Insufficient Filtration

The water flow through the filter makes the water safe for your tank inhabitants. A tank filter should pass all the tank water through it at least thrice an hour.

If it does not do that, it is too small for your tank size. In that case, change the filter and bring a larger one. Because under-filter can be harmful to the fish.

6. Overfeeding The Fish

This is the most common mistake that tank owners do – they overfeed the fish. Understand that the fish will always seek food and will eat it whenever you give them food. But it does not mean that they are really hungry or they need to be fed.

Feed them only as much as they can eat within 5 minutes. If there is any food after 5 minutes, remove it with a net. And give them less food next time.

During startup, give food to your fish once a day. When nitrate and ammonia levels become high, stop feeding for at least one or two days to decrease the amount of wastes produced.

Do not worry about your fish, they can survive days without food and it will not have any bad effect on them. Once your tank is cycled and the levels of nitrate and ammonia are back to zero, start feeding them twice a day.

7. Putting Too Many Fish At Once

Again, out of excitement, you might end up adding too many fish at once – another common and big mistake. Because your tank cannot accommodate a lot of fish at once until the colonies of the beneficial bacteria are fully established.

Start with only a couple of fish. Then add a few per week AFTER the nitrogen cycle has taken place.

8. Not Testing And Changing The Water

It is very common for a beginner to be unaware of the importance of testing the water for nitrate and ammonia levels and changing the water on a routine basis.

But these common mistakes can have drastic effects on your tank inhabitants. So, learn about all the maintenance requirements of a tank and perform each of them to get a tank full of healthy and thriving fish.

Final Words

If you have read the entire article, I am sure you have got a pretty solid understanding of how and when you should start adding fish to your new reef tank.

If you follow the above steps properly, you will be able to stock your reef tank successfully. But most importantly, before you start adding fish, do some research on the needs of the fish you desire to keep in your tank. For achieving success in the long run, stock your tank slowly.

Remember, how successfully you will be able to keep fish in your tank depends largely on what type of fish you choose and how you introduce them to the tank.

With a good setup and a little bit of your care, effort, and patience, your reef tank and its inhabitants will thrive and you will enjoy a beautiful mini ocean view at your own place.

Leave a Reply

Your email address will not be published. Required fields are marked *