Decoding the confusing world of Macronutrients in the reef tank


Macronutrients in the aquarium, what does that even mean? What are macronutrients? How do I get them in my tank? How do I figure out how much I need? These are all questions I had, and questions that you probably have too. So let’s start here, Macronutrients are the elements calcium, alkalinity, and magnesium. While these elements are referred to as macronutrients they make up a very small percentage of not only the water but even it’s content in the salt is less than 10%. These nutrients are required by stony corals for skeletal growth. 

These nutrients are prevalent in salt mixes and fresh saltwater. For tanks with a small number of corals, water changes are sufficient enough to replenish the used up nutrients. However, for tanks with a less rigorous maintenance schedule or more corals dosing or the use of a calcium reactor is required. In order to determine which method is best for you, you will need to test your water. If you begin to notice your calcium is under 380 and your alkalinity is under 7 in between water changes then you will most likely need to dose your aquarium. 

When it comes to dosing I like the easy to use Seachem Fusion 1 and 2. This is an easy way to begin dosing with just two bottles that are hard to overdose. The general rule of thumb is to use half of the dosage that is recommended to begin and test two days after and then again two days after the first test. Based off those results you will determine if you need to increase or decrease your dosages. It is typically recommended that you dose once a week, however in more demanding tanks you may need to dose more frequently. 

Now that we have talked about Macronutrients we can talk about Micronutrients in the next article. Stay tuned and also check out our coral on the rest of the site.

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