Increasing calcium levels

[chase33]

I've added a few sps frags to my tank over the last month or so and I notice my calcium levels have decreased . The last two times I tested they were at 350 and I've had one reading of 320. I change about 15% (considering the water in the sump) of the water weekly. I want to get the calcium level up to around 400 or more if it won't harm the specimens. What are the different methods I could use to increase the calcium levels and how do each work? Also, how many of you add supplements to your tanks?

 

[mladencovic]

While normal source of Ca in aquariums are from

- salt mixes through water changes, and
- dissolving of sand and rocks

this is not sufficient for corals that are building coral skeletons, in which case Ca is usually added to the tanks in the following ways:

• liquid Ca supplements
  Dissolved Ca salts are dosed in the water.
  
  Expensive, should be used only in small systems with regular water changes and alkalinity corrections, since it will affect it. Difficult to keep the balance, and pain if regular dosing needed
  
• two part liquid supplements
  You dose both Ca and Alk components separately.
  
  Expensive if buying prepared components (Ca and Alk) like B-Ionic parts 1 and 2 or Kent's part A and B. Cheap if you prepare components yourself. Pain if manually dosing. Could be automated for 150-200$ . Very good for keeping balanced Ca and Alk. You have full control of what you are adding. Needs occasional addition of Mg. Can be sufficient for any Ca need.
  
• Ca reactor
  CO2 is induced in the tank water in small amounts, which is then passed through reactor media (Aragonite sand for example). CO2 lowers the pH of water so that it dissolves the reactor media faster.
  
  High upfront cost (400$-500$ and up), but then extremely low upkeep cost. If properly adjusted it could be "fire and forget" for months. Produces very balanced Ca and Alk and will satisfy the needs of any load of corals.
  
• Kalk dripping
  Lime is dissolved in water creating Ca hydroxide (limewater-kalkwasser) which is then slowly dripped into the aquarium system (usually sump) because of its very high pH (~12). Usually combined with the top-off water (freshwater) used for replacement of evaporated water.
  
  The cheapest way and is easy to set but needs constant mixing and careful dosing and monitoring, unless you use kalk reactors and controllers which can add hundreds of dollars to the cost. If used only with top off water, it will not satisfy the needs of heavy loads of stony corals, but might satisfy if you have only a few of them. Good for maintaining high pH. Often dosed during the "night" when the pH has the tendency to drop.
  
  

In the end, all of those solutions have their advantages and disadvantages. They all can also produce very negative effects if not properly set, dosed or maintained. That is why, very often, people combine several of them so that they balance each other (for example, Kalk reactor that raises pH with Ca reactor that lowers it).

Research the web and this forum (there have been plenty of threads here) for any more details. Figure out what exactly you want to do in the future and there will be plenty of experience here to help you with whatever you choose

 

[chase33]

Thanks for the detailed response.

 

[mladencovic]

Thanks for the detailed response.

That is in no way detailed , just an overview. For the real details, you have to start researching further, to figure what is best for you ;D

 

[RichT]

This tool will help you figure out how much you need of your favorite supplement or help you adjust you reactor. Good Luck, HTH.

BTW, the flash version works well for me.

 

[Carlo]

I'll only add one thing. Use the calculator RichT pointed out for your product of choice to determine dosing. Make sure to add both an alkalinity product as well as a calcium product to keep them balanced and occasionally check your Magnesium levels and dose this too as needed (way less often then Ca/Alk).

The other suggestion I'd make is to check your pH at night after the lights have been out for a couple of hours. If the pH is under 8.2 I'd consider using limewater as the first course of additions (does both Ca and Alk). Limewater is good for holding levels but not good for raising them.

Carlo