How much Calcium to add to R/O Water?

I've switched to soft water and I bought some Ca-Libur calcium supplement to make up for that.

The label says to feed 10ml per L, which is a ton. I added 2ml per L and the water became white.

The PPM went up by about 100-200, I think.

So, I'm really not sure how much to add to make up for the soft water.

I'm using Bio-Nova Soil Supermix besides that, 1-2ml per L.

Thanks.

The idea or concept of adding back a buffer for for RO water is only "needed" for hydro applications!

RO is stripped of all or most of the dissolved compounds in the water by the process it's self. The lack of Ca makes for a "buffering problem" with the water. The lack of ability of the water to "hold" a pH value is tied to that. It also gives a shortage availability to the plant with both Ca and Mg which are found in water/soils and soils respectively.

If your soil of choice contains a Ca. You have no real need to add a Ca source to the RO water!

If you use RO for any hydro application -You must add a Ca/Mg product. This in even more critical with Coco use as a media!