The Big 3 Ca, Alk, Mg Maintaining parameters in the aquarium

Calcium Used by corals to build hard skeleton base o Corals need calcium carbonate to build their skeletons Used mostly by SPS and LPS corals and hard algae (coralline) Proper range in the aquarium: 400ppm to 450ppm STABILITY IS KEY Can be tested with most commercial test kits o API, Salifert, Hanna, Red Sea…

Alkalinity Total alkalinity is defined as the amount of acid required to lower the pH of the sample to the point where all of the bicarbonate [HCO 3 -] and carbonate [CO 3 --] could be converted to carbonic acid [H2CO 3 ] – Randy Holmes-Farley

Alkalinity An indirect measurement of the amount of carbonate in the aquarium Used by all corals along with calcium to build their skeletal structures Proper range in the aquarium: 8dKh to 10dKh o 2.86 meq/l to 3.57 meq/l Can be tested with most commercial test kits o API, Salifert, Hanna, Red Sea… Works inversely with calcium o As alkalinity goes up, calcium goes down unless a proper balance is kept

Alkalinity If alkalinity gets too high too quickly it will precipitate calcium in the water o Looks like it is snowing in the aquarium STABILITY IS KEY!!! o It takes months for corals to adapt to new alkalinity so rapid changes can cause Rapid Tissue Necrosis (RTN), Slow Tissue Necrosis (STN), or slow/no growth

Magnesium Used by all life in the aquarium Helps maintain a proper balance between Alkalinity and Calcium Higher magnesium prevents alkalinity and calcium “swings” in the aquarium Proper range in the aquarium: 1350ppm to 1450ppm Higher Mg can cause Calcium to be “super saturated” in the tank o This is a good thing! o More calcium and more Alkalinity leads to better coral growth

Maintenance It is VERY important to maintain proper and stable levels to having a thriving reef There are numerous ways to maintain these values o Frequent water changes o Calcium Reactor o Dosing

Water Changes Used in a low demand tank (few LPS and SPS corals) Can be done daily (automatically) to maintain any tank Pros o Helps stability in the tank o Other bad stuff is removed during a water change o Adds other trace elements needed by all life Cons o Too much time! o Tedious When doing water changes make sure your new water has the correct levels of these 3 components o Not testing the new water can lead to low levels over time

Calcium Reactor A way to “recycle” coral skeletons back into the system Media is dissolved in low pH water to replenish all elements needed by corals Pros o Keeps Alk and Ca at proper levels o “Set it and forget it” o Low maintenance once it is up and running Cons o Normally only for larger tanks 75+ gallons (smaller tanks may have low pH issues) o Reactor failure can kill your entire tank o Initial setup can be tricky and frustrating o Many people use Kalkwasser to offset low pH issues o May still need to dose for Magnesium in high demand tank

Dosing Maintains proper levels by adding pre-mixed chemicals to aquarium Calcium – Calcium Chloride Alkalinity – Sodium Carbonate o Baking Soda Magnesium – Mg Sulfate, Mg Chloride or a combo o Espom Salts o Adding too much may raise the salinity of the tank, so be sure to test Various companies make pre-mixed 2-part products o Some contain more than just Ca and Alk which may help other areas Can be added manually each day or use a mechanical doser to automate

Dosing Pros o Finer control over all 3 parameters o When done with a doser, parameter remain very stable o When using a doser, chemicals can be added in small amounts 24 times a day limiting swings in parameters o Wider variety of dosers on the market now so prices will come down Cons o When done manually parameters may vary too much o When done manually precise measurements are difficult o Doser requires regular maintenance to verify it is still working properly o Chemical containers need to be refilled monthly o Chemicals can become costly over time o Accidental over-dosing can cause huge problems o Determining amount to dose can be tedious in the beginning

Dosing Determining how much to dose o Be sure parameters in the aquarium are at normal levels If not, add chemicals manually until they are correct o Wait 3 days, don’t add any chemicals to the tank o Test all 3 parameters o Using a reef calculator determine how much chemical you will need to addreef calculator o Divide that amount by 3. This is how much you will need to dose each day o After 1 week re-test all 3 parameters and verify they are still correct Modify doser settings as needed

Dosing Tips and Tricks o Do not dose both parts at the same time This can cause calcium to precipitate out of the water o Do not dose both parts in the same area of the tank Do not dose near a return pump o Split dosing up to small increments to limit alkalinity and pH spikes o Check the doser after each water change to verify it is still working properly and doesn’t need maintenance Tubing isn’t clogged Check valves still work properly (if used) How To: Dosing Two Part in Your Reef Tank