What is the difference between Kalk and calcium additives?

[ardenen]

Hello... this is a really dumb question, but in my search of the forum I couldn't put my finger on what exactly Kalk was and how it differed from calcium, strontium, and molybdenum additives.

Why does it seem like (in all the posts I've read here) kalk is vital to the proper growth of clams?

I'm just wondering if I should run out and buy some and also try to figure out a way to put it into my system. I'm currently trying to grow a small Maxima clam, who seems to be doing fine right now, but it beeing the first clam I've had I don't know the tell-tale signs of how well it is.

I also have some zoos, pulsing xenia, star polyps, and a sps coral that I forgot the name of (it's pink and when it grows up it should form branches), so I do add some calcium, strontium, molybdenum, and iodine about once a week.

Should I even worry about Kalk?

 

Tank specs:

 

5gal hex acrylic aquarium

10lbs live sand

5lbs live rock

rio 90 powerhead

HOB power filter (with all filter media removed and some LS in the bottom).

1 13w 6500K PC

1 13w actinic PC

3 19w 6500k PC

[chufa]

Kalk is short for kalkwasser, or calcium hydroxide, a.k.a. pickling lime. It adds calcium ions. If you are already dosing another form of calcium, it may be redundant.