Tritonian,
regarding the NaHCO3 concentration, I use a real solution, no suspension.
What means that there is no solid material (powder) left in the water, it's a clear
solution. You could/should use the above (Iwans posting) concentrations of chemicals.
Personally, I use higher concentrations, because I want to dose less volume.
NaHCO3 I use about 82 g/l (gram/liter) which is somewhere near the max. solutability of NaHCO3 (you can't get more of it in the water).
CaCl2*2H2O and MgCl2*6H2O are very easy to solute in water in high concentration
(be careful, it's an exothermic reaction, means getting hot!).
NaHCO3 is as shown above not very good solutable, so you'll have to mix (little pump?) it for
quite a while to get in solution.
Yes, I use the chemicals, pharma grade (pureness). There are also "technical" grade (i.e. less pure) and of course also higher qualities around.
I use a balance to get the right amount and put it in the container, I later dose from and fill
it with water (knowing how much water gets in there).
Concentrations like the ones mentioned prior in this thread should do fine.
As described there, you should dose same amount of CaCl2/NaHCO3/NaCl-free-Salt solutions.
MgCl2 would be less than that (all of course depending on your system).
You'll have to start with a certain dosing (as prior in this thread) and do daily tests to adapt
to the right dosing-volume (i.e. Ca/Alk is still dropping, so add more solutions.... Ca/Alk is raising, so add less solutions. Same with Mg). Later, testing once a week will do.
If Ca/Alk are raising/dropping differently, simply change the dosing independently.
The amount of NaCl-free-Salt should follow the amount of NaHCO3 solution, not that one of CaCl2.
Btw. it's highly likely, that they will develop differently if also adding MgCl2.
When getting started or later if to correct concentrations for whatever reason,
there are online-calculators around which tell you how much (gram) chemicals to add,
to get the desired concentrations.
http://www.aquaterrashop.de/onlinerechner.php unfortunately in german language. (fields in calculator are: (1) measured Ca in g/l, (2) wanted Ca in g/l, (3) water in tank in liter). It answers with (1) CaCl2 to add, (2) NaHCO3 to add, (3) NaCl-free.Salt to add
I don't use them at all, having to low figures, I simply add more solutions.
Knowing about some chemical reactions etc. you can calculate them on your own.
Having molecular weight of Ca / CaCl2*2H2O etc., concentration, wanted concentration and water amount, it's up to some "rule of proportion" calculations.
Pls. if using this method, never put solutions at same time in the water. Wait
some time between dosing, else they will react with each other and not with
your water.
Best,
Ralf