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Do you use a Marine Hard Coral Additive? (i.e. calcium, kalkwasser,etc.)

Jan 4, 2006
I have been researching all the cuttle articles I can find (TONMO, the ceph page, goggle) and can't find anyone recommending calcium.

I was thinking how does the cuttlebone grow without calcium added? I understand why octos wouldn't need it, but that cuttlebone has to grow awfully large-awfully fast. Could that be a limiting factor in the raising and breeding of cuttlefish?

I noticed in some of Colin's photos he had corals, did they receive additives? I also noticed that the brand name "Fuji Mud" is talking about the calcium and minerals in mud patched just outside the reef systems.
This is also where cephs like cuttles and muck animals mostly live. Could they need these conditions to thrive?

Unless anyone can give me a reason not to do this, I am going to try supplementing my tank as if I was stocked with stony coral. I will be learning how to track absorption of calcium, so I can see if it is actually being used.
I think it's supposed to be small enough that the water test kits cannot detect even a trace of it. Not sure about the exact amount though...

Speaking of Calcium, I've also seen a friend of mine use it as a PH buffer or something...not sure is it good for the coral and fishies though (not cephs, he says he'd rather eat them than keep them.)