Nick, I will explain.
The Balling method contains three solutions, best dosed by a automated 3-part doser like the one from Grotech.
*Solution one contains CaCl (Calcium part)
*Solution two contains NaCo3 (Carbonate part)
*Solution three contains MgSo4 and MgCl (magnesium part)
I buy the salts for the solution in Germany. These are Pharmaceutical-grade salts. That means they are extremely pure and almost free of any heavy metals etc.
Brand-name Balling salts can also be used but you pay a higer price for the same product.
IMO it is not safe to use salt that is ment for your driveway etc. since it isn't pure enough for aquarium use.
Beside the salts there are also three mixtures of trace-elements. Two of the mixtures are added to the Ca-solution and the other with the Co3-solution.
I use half of the prescribed amounts and dose extra by hand. I like to have some control and I can never overdose this way.
Solution One and Two (Ca and Co3) are always dosed in the same amount. (for example; 30 ml solution one + 30 ml solution two per day)
Magnesium is dosed seperately.
To determine the exact dosages check the Alk daily and the Mg weekly for some time untill parameters are stable.
In time the demand for Ca, Alk and Mg can rise so check all the parameters frequently to ajust the dosages.
Because only Ca and Co3 is taken up by corals, Na and Cl ions will build up in the tankwater.
Thats why you have to add a small amount of NaCl-free salt to your regular salt when you do a waterchange. This way you prevent the buildup of Na and Cl ions.
with this "Balling-Rechner" (German for Balling-Calculator) you can calculate the amount of NaCl-free salt you have to use in relation to your solution dosage:
Balling Rechner
Leonardo