lastlight's 404

[Delphinus]

Originally Posted by lastlight

So I finally did some tests last night:

Ca - 350
Alk - 10.5
Mg - 1500!

I haven't dosed Mg in ages so Reef Crystals must be high or I need a new kit. Since RC is for sure high in Ca the reduced water changes seems to have lead to a lowered Ca level which I think (I'm not a chemistry guy) means that the corals can't use Alk so the previously acceptable dose was more than needed.

Weird. I don't get that kind of Mg reading my Reef Crystals, I get more like 1150. (I have to add a fair bit to get my w/c water to 1500, which nicely keeps up with Mg consumption to leave the tank at around 1400). I wonder if your kit is off.

IMO, nothing hugely wrong with Mg at 1500. Higher than ocean readings but some things seem to really appreciate Mg around there (I can tell by looking at my anemones if my Mg drops down to 1100 or lower).

Alk is a *little* high and Ca maybe a *little* low but quite within tolerances. I'd adjust my Alk dosing downwards and my Ca upwards by a tiny bit and see how things go from there.