How To: Dosing Two Part in Your Reef Tank

January 10th, 2014
So why do they call it two part when there are really three parts? Why can't I mix everything and add it to my tank? These questions and more will be answered in this episode of BRStv.

Maintaining calcium and alkalinity in your saltwater aquarium is essential to the health and growth of your corals. Corals use these elements to produce their skeletal structure and once they consume it, you will need to replenish it. Also, all the creatures in your reef tank require stable alkalinity and pH to thrive. Two part dosing is a great way to achieve this consistency.

Mixing the solutions is easy. Bulk Reef Supply has a 2 Part Calcium & Alkalinity total package with includes the dry materials as well as the jugs to do the mixing and storage. Follow the instructions in the video and always make sure the solutions are completely dissolved before starting your dosing regimen. Note: Never mix the calcium and alkalinity to dose one solution. As soon as you mix them, the would instantly precipitate out and the solution would be useless.

Most reefers keep the calcium of the tank around 420 ppm, alkalinity between 7-10 dKH and Magnesium at 1350 ppm. First determine the levels of your tank. Using the BRS Reef Calculator you can easily get directions on the proper dosage to increase your levels. Once your levels reach the desire amount, it is then essential to maintain those levels and that is where daily dosing comes in. You'll need to determine the amount your tank is consuming. First start by determining the volume of your tank and sump and whether your tank is high, medium or low demand. We recommend starting with a lower dose, testing and then raising the dose if necessary. It is always easier to add more than take away. Test and adjust, test and adjust, until you find the proper levels have stabled.

Once you figure out the amount to add, always add it to a high flow area of the tank. Make this part of your daily schedule like feeding - do it all at once. So the final step in all of this is Magnesium. Magnesium is not consumed at the same rapid rate as calcium and alkalinity. Magnesium is important because it is the presence of magnesium that allows us to maintain high levels of calcium and alkalinity in the first place. So after you have dosed all calcium and alkalinity solutions (1 gallon of each), it is time to dose 20 ounces or 2 1/2 cups of the magnesium solution. Again, do this in a high flow area of the tank or in smaller amounts over time (but this isn't necessary). You won't need to dose magnesium again until after you dose another full gallon of calcium and full gallon of alkalinity.

Making this process easier on yourself can be done by automating it with dosing pumps - one pump for each solution (calcium and alkalinity). Add an inexpensive outlet timer or control the function through an Apex or ReefKeeper. Bubble Magus, Vertex and Fauna Marin make dosers which can be programmed to your specific needs.

Are you dosing two part in your reef tank? What is your set up for two part dosing?