buffering idea for sump?

[Nameless]

I'm going to be transitioning my fowlr tank to a reef at some point in the future. I was worried a bit about calcium, so I thought of this idea, and I'd like some comments on it. What if you hung 'curtains' of cc in your sump that water passed through? Would this add sufficient buffering and calcium without the need for additives?

 

[SeaMac]

I'm sure you'll get a better explanation from the chemistry buffs around here, but I don't think it will help very much. Assuming you keep the pH of your tank somewhere in the 8.0-8.4 range, very little of the calcium carbonate in the crushed coral will actually dissolve at this pH. Calcium reactors work in a similar fashion to what you are describing, and require a pH of 6.5-7.0 to function properly (i.e., dissolve enough calcium to maintain adequate levels in the tank).

I suppose you could try it anyway, but be prepared to either add a 2 part additive for calcium and alkalinity or to dose kalkwasser.

Hope that helps.
Chris

 

[2poor2reef]

For that same reason I never bought the idea that aragonite sand helps buffer our marine systems.