Another question if you don't mind regarding my low tec plant.
Melbourne's water is 3 degrees GH according to my test kit.
I am happy with these levels for both flora and fauna in my tank.
With time (as i don't anticipate doing water changes) GH levels will drop.
I will then need to supplement GH levels.
My understanding is that 0.79g CaCl2+0.33gMgSO4=1 degree GH

This formula gives me a ratio of Ca/Mg of 7:3.

ie. I will need to add 11.85g of CaCl2 to obtain a 0.7 degree increase in GH (or 12.6ppm) and
4.95g of MgSO4 to get a rise of 0.3 degrees in GH (or5.4ppm) in 150 gallons of water.

Is this correct if i want to increase GH by 1 degree?

I note in the fertilator , if i key in 11.85g CaCl2 in 150 gallons water my Ca++ reading is only 7.74ppm and for MgSO4 4.95g gives 0.86ppm of Mg++.

My understanding is that GH test kits measure in CaCo3??
To obtain the actual Ca++ and Mg ++ in ppm you need to divide Ca by 2.5 and Mg by 4.1. Is this correct?

LAKA

The likely problem, especially with Cl, is the build up, whereas the same effect is not present in the SO4 build up, plants will consume/assimilate both anions in tissue, but seem to be less sensitive to high SO4 vs Cl.

Note, this is mainly speculation, no one has shown this. Still, thr evil I do know and use is the GH booster or Seachem's Eq.

Both of which use all SO4's for the anions in CaSO4, MgSO4, K2SO4, FeSO4 and MnSO4. But a little Cl is not bad and helps, same with a little sodium, but it should be fairly low. So adding some KCl, or CaCl2 every so often will not hurt too much.

Adding the GH booster works very well. I really have not done enough with Cl isolated to say much with many species.
Same with Zn, MN, Na, SO4, etc.


Regards,
Tom Barr

Thanks for the advice on Cl Tom. I do however need to know if my dosage calculations are correct for increasing GH using CaCl2 and epsom salts.
LAKA