Hello,


I read that you can lower water hardness with Oxalic acid. Here is what
i did.
Tested my tap water: 19 GH or 338,2 ppm calciumcarbonate with a pH of
+7,6
after 20g oxalic acid in 5 liters (1,3 gal) and a day of rest it came
down to a GH of 3( 53,4 ppm) and a pH lower than 6 and a nice deposit
of calicumoxalide on the bottom which I removed.
I am now testing the same with 10g on 5 liter to mesure the results but
I don't have the results yet.

Now my question is

How do I know what is a good amount of oxalic acid for a given amount
of water?
Is all the oxalic acid used up in the process?
Is there anything essential changed in the composition of the water
(apart from ph and hardness)?
Should I use sulphuric acid or any other product?

Thanks for any reply