Best Additives For Reef Tanks (How To Choose The Right Ones)

For anyone currently running a reef tank, you know how important it is to supplement your tank with the necessary additives to keep things vibrant and healthy.

Corals will naturally absorb elements like calcium and magnesium which must be replaced in order to avoid depletion and keep levels within proper limits.

Without replenishing trace elements, your corals will suffer and you won’t be able to achieve the long term success that you are looking for with a coral reef tank.

Sure you can rely on water changes to help replenish some elements back into your tank. But as your reef matures, water changes won’t be enough. Even if you use the best quality salt on the market. 

So accept the fact now that if you are going to have a reef tank long term, dosing is inevitable. We all need to do it.


But the question is what are the best additives for your reef tank and how do you add them into the tank properly? 

This article will explain in detail which additives are important to use and how to choose the right ones correctly.


The major elements that need to be constantly replenished in your reef tank are:


  • Calcium
  • Magnesium
  • Carbonate
  • Strontium

Other minor trace elements include:

  • Iodine and Iodide
  • Iron


There are only 2 ways or methods that you can choose from when dosing your reef tank. 

  • Manual
  • Automatic

Both methods are effective and both have their pros and cons.

Manual dosing is where you manually add the supplement into the tank by hand. Which is fine but there are a few problems with manual dosing.

The first being able to remember to do it on a consistent basis. Many people will forget or simply get busy and don’t do it.

Manual dosing is also not as accurate or effective as automatic dosing. I find that many people who manually dose their tank will get frustrated by doing it and will switch over to automatic dosing. 

Automatic dosing is where you use a dosing pump to automatically add the supplement to your tank at a set rate and time throughout the day.

The automation will replace the elements as they are being depleted. This is the most convenient and effective way to dose your tank.

Water stability is crucial for keeping a successful reef tank and with all the advanced equipment in the hobby today, using a dosing system on your tank has never been easier. 


Supplements for your reef tank – Major elements (Calcium, magnesium, carbonate) 


There are so many different brands of supplements available to use. I will only mention the ones that I have personally used and have had great success with. 

I recommend the Aquaforest Component 1+2+3+ supplement or the Red Sea reef care program. 

For supplementing your tank with the big 3 elements, both Aquaforest and the Red Sea are great choices. They are very popular in the hobby, readily available, and affordable. They contain all the necessary elements your corals need. 


Aquaforest Component 1+2+3+


Not only does the Aquaforest system contain the necessary calcium, magnesium, and alkalinity elements, they also contain other trace elements.

Component 1+ contains: Ca, Sr, Ba, Co, Mn, Cu, Fe, Zn, Ni, Cr.

Dosage = 25ml dissolved in 100 l/27 US gal raises Ca by 4.5 mg


Component 2+ contains: NaHCO3, F, I

Dosage = 25ml dissolved in 100 l/27 US gal raises KH by 0.65 dKH (Alk: 0.23 meg/l)


Component 3+ contains: Mg, Reef Mineral Salt, K, and B

Dosage = 25ml dissolved in 100 l/27 US gal raises Mg by 0.38 mg/l


The Aquaforest Component 1+2+3+ comes in 3 separate 5L bottles. The system is designed to dose equal amounts on a regular basis. It is available at Marine Depot. 


aquaforest component 1+2+3+


Red Sea reef care program


The Red Sea reef care program was created from many years of research looking into the specific demands of all saltwater coral types.

The Red Sea ABC supplements provide a complete solution for maintaining your Calcium, magnesium, alkalinity within optimum levels for your tank.

Reef Foundation A contains calcium, strontium, barium in the ratios as found in coral skeletons.

Reef Foundation B contains bicarbonates

Reef Foundation C contains magnesium

Reef Foundation ABC+  contains Calcium, Strontium, Barium, Bicarbonates, Magnesium, Potassium, Boron, Iodine & Bromine formulated in the exact ratio as found in the coral skeleton. This unique powder supplement simplifies the daily dosing of more than just the foundation elements. 

You can download a pdf copy of the Red Sea reef care program here. It is available to purchase at Marine Depot.


red sea reef foundation




All tanks will have different needs and no 2 tanks will be exactly the same. But you should aim to maintain the following parameters.

Alk 8.5 dkh (8-12 dkh range) Try and keep this in balance with calcium. For example, if you end up using the lower end of this scale then you should aim for the lower end range of calcium.

Magnesium 1300 ppm (1250-1450 ppm range)

Calcium 440 ppm (380-470 ppm range) remember to keep in balance to alkalinity.




What is the best salt mix for a reef tank?


As we know, salt is necessary to have a saltwater tank. But not all salts are the same. Some are better than others with respect to the trace elements within the salt.

If you have a fish only tank, then the brand of salt and elements is not as crucial as if you have a full reef tank. 

You need to ensure the salt you are using contains the proper amount of elements you need. My favorite salt to use is the Red Sea Coral Pro and Red Sea Reef.

They both contain the necessary elements, both are easy to mix, and are affordable. 




How fast can I raise ALK in a reef tank?


It’s very important that your water parameters stay as constant as possible without fluctuations. After testing if you notice that your alkalinity is low, you can raise it by using a few methods.

Using one of the additives mentioned in this article will increase the alk level. You want to raise your alk slowly and no more than 1dkh per day.

You can increase this slightly, but for best results, limit the increase to 1dkh per 24 hours. 


What are the best 2 part dosing supplements?


You will often hear the term 2 part with respect to reef tank dosing. 2 part refers to calcium and alkalinity which are what most new hobbyists will be concerned with during the beginning stages of setting up a reef tank.

 If you are only looking for 2 part dosing supplements, check out ATI Essentials Pro. It is available at Marine Depot here



When choosing the best additives for your reef tank, you have so many options. You can purchase certain supplements separately or in a complete kit.

The important thing when dosing these supplements into your tank is to monitor your levels and make sure that any changes are made slowly over time.

The additives mentioned here are all proven to be effective and will give you the results your tank requires.

I recommend the use of a dosing pump to make your dosing convenient, accurate, and on schedule.