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View Full Version : chelating reef salt?

reefkeeperrut
01/11/2007, 07:28 PM
I spoke to a mnf rep from the salt co. I use and they say b/c their salt has chelate binding calcium it is much easier to be used by corals and corraline. According to him because of its chemical composition the calcium is roughly 5x more likey to be used by corals rather than ionicaly bound within the sea water. And b/c of this composition I can not add calcium and mg supplements to the make up salt water b/c the calcium will precipitate. Rather I should be adjusting my paramteters via the sump and/or display which I would prefer not to do.

Out of the box at 1.024 it reads 390 Ca, 8.0 dkh, and 1280 Mg. I would like to bring Ca nd Mg up a bit but I can't do this to the make up b/c of precipitation.

Hoping someone can help me understand the chemistry facts from the marketing b/s.

Thanks
reefkeeperrut
01/12/2007, 05:32 AM
anyone?
Randy Holmes-Farley
01/12/2007, 07:31 AM
According to him because of its chemical composition the calcium is roughly 5x more likey to be used by corals rather than ionicaly bound within the sea water.

Is that exactly what he claimed? I could make something that was more likely to be used by a coral than to be precipitated as calcium carbonate, but still be something that corals did not care for as much as natural calcium ions. So that statement might even be correct (although I expect it is actually nonsense not supported by any real data), but it does not suggest that you'd want such a material in your tank.

There is no evidence that I have ever seen that corals benefit from chelated calcium, and frankly, I'd be more inclined to guess that it will make it harder for them to use it, not easier. The transporters that corals use recognize and bind to ionic calcium, not chelated calcium.

If they have a weak chelator, it probably falls off in the water. IF it is a strong chelator, I would not want it in my tank at levels approaching the calcium concentration.

I discuss calcium uptake by corals here:

The Chemical & Biochemical Mechanisms of Calcification in Corals
http://www.advancedaquarist.com/issues/apr2002/chem.htm