Raising Nitrates in Reef Tank

Raising Nitrates in Reef Tank – 4 Simple Methods

Corals are way too sensitive to nitrate levels. Moreover, a low nitrate level in your reef tank can cause havoc. It can be heartbreaking to see your corals get decolorized and struggle to grow. We aquarists face this problem quite commonly.

So, how to raise nitrates in reef tank?

One of the most natural methods is to feed more food in your tank. Increasing the number of fish also can be a great way to raise nitrate. Another way is to cut back filtration in your reef tank. However, the most efficient and effective method of increasing nitrate is using external supplements. 

The methods mentioned here are explained to a great extent in this article. You should try to study these methods before picking the right one. Let’s get down to business and raise your tank’s nitrate level!

What is the Optimum Nitrate Level for a Reef Tank?

The adaptability of various species in different environments differs a lot. In a reef system, you can see this with your own eyes. 

Nitrate is a key parameter for your aquarium’s environment. It either helps the population or harms them. Nitrate level is a very sensitive aspect of a reef system. Even a slight change in nitrate level can kill your corals or other invertebrates.

Fishes have better tolerance to nitrate levels. They can survive up to 40 ppm of nitrate in saltwater tanks. If your tank is a fish-only tank, then 30 to 40 ppm is the optimum range.

Then again, corals can not survive in this type of high nitrate level. The ideal nitrate level in reef tank for corals is much lower than that. It is considered to range between 0.25 to 5 ppm. 

Many experts suggest keeping the level between 2-5 for better coral coloration. I am following that too, and it’s been as vibrant as ever.

This is such a delicate matter and should be monitored daily. Here are some testing kits that I’ve used to test my saltwater tank. 

Digital kits might seem convenient, however, chemical ones are great as well.

Is Low Nitrate Level a Problem?

Nitrate in the reef tank is the result of the Nitrogen Cycle. Ammonia that comes from fish waste is converted into nitrite by filter bacteria. Then it turns into nitrate. 

This nitrate is then consumed by plants. Thus, the balance inside our reef tank remains intact. 

However, nitrate levels can reduce in your tank in many ways. An excessive amount of algae, a lower number of fish in the tank, or other issues. 

This dip in nitrate level can be a problem for your corals. As they are not used to extremely low levels of nitrate in oceans 

This situation may result in coral discoloration and halt their development. Even this can cause problems like, corals staying shut.

It’s important to keep everything in balance in your reef tank. For your corals’ betterment, nitrate levels should always be kept in check.

4 Methods to Raise Nitrates in Reef Tank

Low nitrate levels can be a nuisance for the corals. There are countless aquarists that tried different methods to increase nitrate in their tank. I’m one of them too. 

Unfortunately, all of them do not work as well as one might think. 

Personally, I’ve tried several processes to raise nitrate levels without any side effects. Here are the methods that I’ve found most convenient and efficient.

  1. Feeding more food
  2. Cutting back filtration
  3. Adding more fish
  4. Dosing external fertilizer

However, the result of these methods may vary from tank to tank. I’ve explained these methods in detail in this article. 

Method 1: Feeding More Food

Nitrates in the aquarium are produced by fish waste. And what should you do to increase the production of fish waste?

Obviously by increasing the amount of food supplied in your tank. The more the fish eat, the more they will make wastes. As a result, the amount of nitrate in your tank will escalate. 

Now you may wonder, what should I feed in my reef tank?

You can feed a variety of foods in your reef system. You can try frozen food, dried food, pellets to give your tank a balanced diet. Powdered food and liquid food also can be an option to feed your tank. 

To make things easier I’ve tried to curate a list of different types of foods that I tested.

So, here we go!

Pellet Foods

Pellet foods are great. Because neither they are powdered nor a big chunk of food. They don’t float inside the tank, thus giving everyone a chance to get a bite.

The pellets spread across the whole aquarium, this keeps everyone in the tank busy. 

These are my picks of pellet foods.

Freeze-Dried Foods

These are not as much used as the previous one. However, some of my fishes used to love these tightly wrapped cubes. These dried foods tend to explode instantly when met with water.

Here’s a tip!

Before feeding, put a few crumbs of these in a shot glass. Then add some aquarium water and let it sit for ten minutes. This is the way I used to dump them in. You may try as well!

Here are some suggestions- 


If you have Tangs in your tank, then these are for them. Keeping Tangs is a great way to enhance nitrate production in your tank. We’ll get to that later. 

They gobble these stuff up like they were never fed! I’ve seen them fight for this even though they were fully fed.

Nori is basically roasted seaweed. They are available in the “ Ethnic Food” aisle in any grocery shop. They are dirt cheap and stay perfect for days.  

I normally store them in Zip-lock Bag. But there’s a catch! Make sure you get the dried nori without oils or any junk.

You can also buy nori that is specifically engineered for your fish. I’ve always used gimMe snacks noris. They are great because your fish can eat them directly and you can use them while making sushi.

Feeding nori can be a problem because it normally floats in the water. So all the fishes in your tank might not get a chance to eat them. And, that’s why I recommend using a Veggie Clip to hang the nori to feed your fish. Here are some great veggie clips for you to consider.

Powdered Foods

It’s equally important to feed your corals, like fish. Powdered foods are specifically great for your corals and invertebrates. When it comes to powdered food there’s a debate between reef roids and coral frenzy.

However, you can use any of the below-mentioned powdered food for corals and invertebrates. I use them regularly in my reef tank. So, you don’t need to worry about the quality.

Corals normally consume their food at night-time. So, dose this powdered coral food in your tank before going to bed. Your corals will show a growth outburst and vibrant colors!

Does This Method Increase Phosphate too?

Increasing nitrate by feeding your reef tank is fun and games. But there’s a problem with that. Adding an extra amount of food will increase other elements as well. 

So yes, the extra feeding method will also give a spike to phosphate levels. 

It’s the last thing you want to be honest. Having a high phosphate level is worse than having zero nitrates. Therefore, follow the directions that the food manufacturers provide. 

Method 2: Cutting Back Filtration

If your tank has a huge amount of plantation, this can be the reason behind low nitrate levels. 

Because plants consume nitrate as nutrients. They remove ammonia, nitrate and nitrite from your tank water. This whole process of removing natural waste from your tank is called the filtration process.

Nitrate is one of the main foods of algae and they consume nitrates rapidly. A vast amount of algae can remove nitrate completely from your water tank.

So, cutting back your filtration system can be a cunning method to increase nitrate. You can reduce some of your plants. Reducing algae can also help you out. 

There are not enough saltwater algae cleaners in the market. However, I am a victim of rapid algae growth. Back then I used Algae Clean Out of Fritz Aquatics to reduce excessive algae.

This process will slowly but surely help you to increase your tank’s nitrate levels.

Method 3: Adding More Fish

We’ve mentioned before that, nitrate levels increase with more fish waste production. Therefore, Adding more fish will definitely increase nitrate production.

However, this is not an efficient method. Relatively smaller tank owners won’t be able to implement this method. Another concern is that it can create chaos in your tank as well.

However, you can try to add some specific type of fish to help you out.

Which Type of Fish to Add?

The fishes with a huge appetite are effective in solving this problem. You can add some fish like this other than adding a bunch of fish. They will eat a lot and as a result, create more waste. 

Tangs are known for their remarkable appetite. Thus, adding one or two tangs will undoubtedly increase nitrate levels. 

Tips & Tricks for Keeping Tang Species | TFH Magazine

Method 4: Dosing External Supplements

People are always worried about adding chemicals to their tanks. As first-timers, it is only logical to be scared. Because chemicals sometimes have an adverse effect on the tank water.

That’s why new aquarists tend to apply the 3 methods that are mentioned before. Then again the increase of other trace elements is a thing to be worried about. Thus it refrains them to try those methods.

But let me assure you, there is nothing to be worried about while using fertilizers. Yes, you can argue about using the wrong fertilizer. And here I’m gonna help you with choosing the right fertilizer to increase nitrate levels in your tank. It might seem a bit confusing to you at first. But bear with me, I’ll carefully explain everything to you.

Here’s a comparative summary of some of my chemical picks. You can choose any of these according to your own preference.

External Dosing MaterialCostDosage to increase 2 ppm of Nitrate in 100LEffectivityPrice
Homemade Sodium Nitrate Solution17-19 $ /454 gm4mlLowGet it Today
Neo Nitro14-15 $/500 ml10.526mlHighGet it Today
NilocG KNO313-14 $/454 gm4.76 mlModerateGet it Today
Spectracide Stump Remover24-27 $/454 gm32.89 mlHighGet it Today

Which One Should You Try?

All of these supplements are worthwhile to use. It is noticeable that some of them are better than others in different categories. 

Neo Nitro is more effective as per customer review and personal experience. But if you consider their dosage rate NilocG KNO3 beats Neo Nitro by miles. 

I’ve discussed the preparation and dosing process for all the chemicals below. You should check that out before concluding a decision.

Homemade Sodium Nitrate Solution

Most of the chemicals mention their ingredients on their container label. But it’s the hidden ingredients that might be confusing.

The fertilizers that you are planning to buy may not have any hidden ingredients. Even then, you can not trust them with all your heart. That’s why nothing is better than using your DIY Solution.

This can be done very easily and without any complex procedure. This is much easier than making DIY Gh Booster. Because you won’t need to buy various chemicals and mix them proportionately. All you need is to buy Sodium Nitrate or commonly known as Chile Saltpeter. 

Dosing will depend on your tank’s volume. You should dose regularly if you have the nitrate level at 0.

Here is an example if you want to increase 2 ppm of nitrate in your tank. Say, you have a tank with 100 L of water in it. You’ll need to dose 4ml of the stock solution.

And to make the stock solution, first, you’ll need to take 500 ml water in a container. Then add 40 grams of NaNO3. Mix the solution thoroughly till all the granules are dissolved in the water. 

Remember that, 1 gallon = 3.8 liters. This relation will help you to measure what your own tank needs.

Neo Nitro

Neo Nitro is a liquid balanced nitrogen source. Often we become worried about the potential spike in phosphorus while adding nitrate. This will not only keep phosphorus in check but also help to reduce it.

It increases the phosphorus uptake for other organisms. Thus letting the increase in nitrate be utterly dominant.  Moreover, You don’t have to make a stock solution. You just have to add 1ml of Neo Nitro to increase the nitrate level by 5 ppm in 1 Gallon of water. 

Let’s take 100 liters as the ideal tank volume and 2 ppm increase static. That’ll help us to compare the other fertilizers’ dosage rates with this one. 

1 ml of Neo Nitro will increase nitrate of 3.8 liters by 5 ppm. So, for a 100 L volume of water, you’ll need approximately 10.526 ml of Neo Nitro. This will increase the nitrate level by 2 ppm.

NilocG KNO3

This is another cost-effective fertilizer to increase the nitrate level. 

First, take 1 teaspoon of KNO3 and pour it in 75ml of water. Then mix it till all the particles are dissolved. This is your stock solution. 

It usually increases 0.42 ppm of nitrate in a 100L tank if you dose 1ml. Therefore, to increase 2 ppm of nitrate in a 100L tank dose 4.76ml.

Spectracide Stump Remover

This might seem an unconventional chemical to use at first. But you need to look at the ingredients of this chemical. It is 100% Potassium Nitrate. So mixing it with water will obviously increase the nitrate level in your tank.

To start making the stock solution, take 1 liter of RODI water first. Then add 10 grams of the stump remover. Finally, stir the solution till all the particles are dissolved. 

And you’ll have your stock solution!

In general, 2.5 ml of this stock solution increases nitrate by 2 ppm of 2 gallons.

And 2 gallons is equivalent to 7.6 liters. Now, for 100 L of tank volume, you’ll need (2.5/7.6)*100 = 32.89 ml. You should dose this amount regularly in your tank till you get your desired result.

Preventive Measures to Keep Nitrate Level at Optimum

Prevention is always better than cure, isn’t it? So, to prevent the nitrate level from going down you can check out these actions-.

Feeding regularly

It is a must for any kind of tank. You have to feed your fish, corals, and other organisms regularly. However, keeping an eye on the amount of food you are putting in is a must. 

Feeding them regularly will not let the nitrate level drop. But make sure that your fish are always finishing what you are feeding. Otherwise, you might see a spike in nitrate level. Because the uneaten food will degrade eventually and create more nitrate.

Keeping a balanced fish population

As we discussed early, the amount of fish is proportionate to nitrate production. So you get it right? It’s pretty simple. If you keep more fish, your nitrate production will rise and vice-versa.

That’s why I recommend keeping a balanced number of fish. Obviously, according to your tank’s space.


What is the optimum phosphate range in a reef tank?

Phosphate levels in reef tanks should be kept at a minimum of 0.05 ppm. And the maximum is 0.1 ppm. It is recommended that phosphate levels should stay within this range.

Should I remove my protein skimmer to raise the nitrate level?

Yes, you should get rid of it for a few days. Because it usually clears the waste released by fish before it can release nitrogen. Don’t keep it out of the tank for too long. Otherwise, your tank’s nitrate level might skyrocket.

Does live rock reduce nitrates?

Bacteria normally live on live rocks. And the more bacteria you have, the more waste will be digested by them. Thus, live rocks play an important role in lowering the level of nitrates. 


Hopefully, we could give you answers on how to raise nitrates in reef tank. All of the methods here are tested and proven. Moreover, all of these methods have their advantages and flaws. At the end of the day, it all depends on your requirements. 

So, be wise and pick the best-suited method for your tank. If you have any further queries do comment down below.

Thanks for staying with me. Good luck!

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