Having some trouble understanding how to use kalk and magnesium…
I have read that magnesium shouldn’t be mixed with high PH additives since it would precipitates, hence my understanding is that you cannot add magnesium directly to kalk solution for drips.
So how is product like brightwell able to incorporate magnesium into their kalk+2?
(2 being strontium and magnesium)
It's not. It's a crazy bad product claim.
Here's a copy and paste from older threads:
Magnesium is not soluble in limewater, so it will just sit on the bottom and worse, the amount present in kalk+2 is not nearly enough to meet the demand for magnesium, and far worse yet, is LESS than is present in many bulk brands of calcium hydroxide as an impurity.
Here's the Brightwell kalk+2 claim:
http://brightwellaquatics.com/products/kalk2t.php
Guaranteed Analysis
Calcium (min) 54.20% (542,000 ppm), Strontium (min) 1.00% (10,000 ppm), Magnesium (min) 0.15% (1,500 ppm)
So that is a ratio of magnesium to calcium of 1:361.
I show in this article that bulk calcium oxide (dried calcium hydroxide) has more magnesium as an impurity (1:263) and that in the actual limewater, the magnesium ratio does not exceed 1:36,000, with the remainder ending up undissolved on the bottom.
Magnesium and Strontium in Limewater
Because of a potential imbalance between the amount of magnesium and strontium used by corals, and the amount delivered by limewater, using limewater can potentially lead to depletion of both ions in aquaria.
I show in this article that a typical coral or coralline aglae incorporation rate is 0.1 to 4%by weight, for a ratio of about 1:400 to 1:10.
This article details the nature of magnesium in seawater, how it is added, measured, and removed from marine aquaria, and how it impacts the maintenance of calcium and alkalinity.
reefs.com
