Ca not California

[varpanus]

calcium. I've heard you gotta have alot for hard corals to grow. you also gotta have a lot for inverts that need to grow shells. But is there a point which your calcium is too high? also, would putting a large shell in your tank leech calcium into the tank?

 

[balogh03]

i am not an expert on this, but i thought i would get you back at the top off the list because i know that somebody around here does.

 

[roblou]

varpanus: yes, Ca is important for hard corals to grow, as they pull the Ca from the water & use it to build their skeletons. Same with clams and others with shells.

I believe NSW is approx 380ppm Ca, and most people keep their reef tanks between 380-420ppm (although I'm sure opinions will vary). Different brand salts have different Ca content (also diff Alk, Mg)...some are lower than desired (IO for instance) and some are higher than desired (Oceanic for instance). So, it's best to test your salt to find out exactly where it stands as far as Alk, Ca, Mg, etc.

Putting a shell in your tank will not leech Ca into the water column. Ca doesn't dissolve until the pH is much lower than what we keep reef tanks at (Ca reactor does just this, uses Ca rich media & really low pH water to dissolve the Ca & put into the water column).

You should definitely have good Ca & Alk test kits (among others), and test on a regular basis. This, along with regular water changes, and possibly having to dose for Ca and/or Alk to keep them at proper levels will provide a very good environment for corals and other livestock to thrive. Too low or too high of either of these is not desirable. But, more important that that, stability is the key...the less fluctuation you have, the better it is.

Ca & Alk additives are numerous. There is also a very good DIY recipe you'll find mentioned all over this site. Check the Chemistry forum for more details.

hth,
rob

 

[DonW]

There is a little more to it than just calcium. Its to high when it becomes skewed above being balanced with alk and mg.

Don

 

[MikeS]

calcium. I've heard you gotta have alot for hard corals to grow. you also gotta have a lot for inverts that need to grow shells. But is there a point which your calcium is too high? also, would putting a large shell in your tank leech calcium into the tank?

Levels above 420ppm Ca don't do much to help coral growth, and can actually negatively impact coral tissue development.

As for the shell...no, not much available calcium will be leeched into the tank. They tend to trap and stagnate water inside, and there are some phosphate issues as well...best to leave the shells out of the tank...

MikeS