Keeping a reef tank can be an enjoyable and rewarding hobby. Your coral and livestock will have a certain nutritional draw on the available resources contained within the tank. There are 3 metrics that are most commonly measured; Alkalinity, Calcium and Magnesium.
There's lots of information that will go into detail about all these, but in a nutshell and for brevity, to get the most from your reef, Alkalinity and Calcium should be dosed daily to offset the consumption. It is commonly called "2 Part" dosing. To figure out how much to dose differs from tank to tank but there are some basics to get you started. We go into more detail below on how to determine what's the proper amount for your tank, below.
If you want your corals to thrive, 2 Part dosing is essential to ensure coral are able to remove acid build up from their flesh and to continue to remove calcium from the water to build their structure. Failure to do so can result in undue stress, stunted growth or in worst case scenarios, death of coral. Everyone has heard of the acidification of the oceans, well dosing is a buffer to prevent the build up of CO2 and thus acids in your reef tank.
The 3rd item, in the 2 Part (confusing I know) is the magnesium. This is checked once a month using hobby reef test kits (links below). When magnesium is low, it will effect the balance of the first two in relation to each other.
1. You'll want reliable test kits. Hanna, Red Sea, Salifert and others are fantastic kits that will give you relatively accurate numbers. A lot of hobbyists like the digital read out of Hanna testers but they come at a high price, while others love the affordability and accuracy of Salifert. I personally love that Red Sea contained all the tests I needed in a single package and under $100, but I have branched out to Hanna. Whatever brand you choose, these numbers will provide you the information required to establish an easy, daily dosing regime that will benefit both you and the coral from lack of stress and you'll have a more rewarding experience with reef husbandry.
2. Ensure that your water is at the proper salinity (salt) concentration and temperature. Most hobbyists keep their tanks at 35 Parts Per Thousand (ppt) or 1.026 specific gravity (a measure of density within the water) in relation to their salt content.
3. Ensure your Temperature is at the correct level. Reef tanks seem to range from 77-81 degrees F but regardless of what you run at, as with everything in this hobby, keep it consistent.
4. The next may take some planning. Determine when in the next week you can test your aquarium at the same time.
5. For the first time, test your Magnesium, Alkalinity and Calcium in that order. Correct the magnesium before you test your alkalinity and calcium.
Most successful reef hobbyists keep their tanks within these ranges.
Magnesium should be around 1250-1350 ppm
Alkalinity 8-12 dKh
Calcium 400-450 ppm
Correct your numbers to the recommended ranges, going slow and being sure not to overdose. Magnesium can be corrected all at once. Alkalinity should be corrected no more than 1 dKh per 24 hour period, break up the dose over a few hours. Calcium is recommended no more than 100ppm per 24 hour period as well.
You can use the BRSTV calculator to help determine your dose. https://www.bulkreefsupply.com/reef-calculator
Our products are made to the same concentrations as the BRS liquid mixes for ease of use. Enter your Total system volume, current levels and desired levels, then choose the following to determine the required dose. Keep in mind that you only need to use 1 of our Alkalinity products, not both at the same time.
Choose "BRS Liquid Magnesium Mix" for Magnesium Boost+
Choose "BRS Liquid Soda Ash" for pH/Alkalinity Boost+
Choose "BRS Liquid Sodium Bicarbonate" for "Alkalinity Boost+
Choose "BRS Liquid Calcium Chloride" for Calcium Boost+
6. Now that you have a base line - figure out a time that you can test and test again within 5 days, at the same time, to determine the draw on these vitals of your tank.
Initial - Test and dose to bring levels to desired levels you'd like.
Day 0 - Test alkalinity and calcium at 7pm, make note of the results.
Day 1 -
Day 2 -
Day 3 -
Day 4 -
Day 5 - Test Alkalinity and calcium at 7pm, compare to the previous results. The difference is the consumption of your tank over 5 days. Take the difference, divide by 5 and that is the daily consumption of your current livestock.
Use the BRSTV calculator, choose your supplement your testing for alkalinity or calcium ( https://www.bulkreefsupply.com/reef-calculator ) to determine the dose to bring levels back up to Initial levels. Dose that. Then use those same numbers, divide by 5 and that is the daily dosing required per day. You can dose these now manually, or set them up on an automatic dosing system.
7. Check your tank every week at the same time. Note the results in a spreadsheet and adjust the dosing requirement UP or DOWN depending on the consumption. Your tank will constantly be changing. These weekly tests will help prevent it from swinging too far in one direction or the other, while allowing you the piece of mind knowing that you're providing the essentials for your coral and tank.
Alkalinity and calcium are generally dosed in the same volume per day, but at separate times to prevent them precipitating out of suspension. Often, people will find out their daily dosing requirement for alkalinity after initial correction, then use that number to dose the exact volume of calcium supplement. After each 500ml bottle of Alkalinity Boost+ or Calcium Boost+ supplement dosed (usually is empty at the same time when dosed this way) you would add 76ml of Magnesium Boost+.
8. Check your Magnesium levels once a month and correct if needed.
Most of these products are cheaper in stores.
Hanna Alkalinity Checker - https://amzn.to/3jpgSTB
Hanna Calcium Checker - https://amzn.to/3HMDkzr
Hanna Magnesium Checker - https://amzn.to/3XVhuPM
Red Sea Reef Foundation Pro Test Kit - https://amzn.to/40hqOiD
Salifert Corbonate Hardness / Alkalinity Test kit- https://amzn.to/40gl8p4
Salifert Calcium Test kit- https://amzn.to/40gl8p4
Salifert Magnesium Test Kit - https://amzn.to/3Yf1EiU