RO water - Supplementing Calcium and Magnesium. What is the ideal ratio and amount?

Hi,

I am using RO water and I didn't used calmag or something similar for my plants.

Hence my plants developed deficiencies.

As calmag is not available in my location I bought Canna Mono Nutrients (Separate bottles of Magnesiums and Calcium).

I read that the Calcium to Magnesium ratio is not optimal in calmag and I was wondering what the ideal ratio is.

I am also wondering how much "ml" Calcium and Magnesium I have to supplement for one gallon or liter?

I could also work with EC values if you can state any.

Currently I am using Advanced Nutrients 3-part in 3-2-1 ratio, EC 1.2, shortly before switching to flower.


Botanicare Cal-Mag Plus recipe: (use up to 5ml/gallon - 1,3ml/l)

Total Nitrogen (N) ….. 2.0%
Calcium (Ca) ….. 3.2%
Magnesium (Mg) ….. 1.2%

So botanicare is using a 3:1 ratio (more or less)


Canna Mono Calcium: 15% calcium (Ca) and is chloride-free (use 1-2ml/l)
Canna Mono Magnesium: 7% MgO and 14% SO3 (use 1-2ml/l)

So if I want to use the Botanicare recipe with Canna Mono Nutrients I only need to use 0.21ml/l of Calcium and 0,22ml Magnesium as the Canna Mono Nutrients have a much higher concentration.

If you compare the Canna recipe with the Botanicare one it is suggesting to use 4,7x times more calcium and 5,8x more magnesium?

Isn't that a bit excessive?

I hope you can help me.

Ca:Mg ratio should be between 1:0.25 and 1:0.40 by mass.

K2O:Ca ratio should be around 1 : 0.5.

You probably won't need to use cal-mag with the amount of AN micro you're using. The micro bottle is mostly based on calcium nitrate, which in the amount you're supplying should take care of your calcium needs.

(cal-mag is a waste of money)