Cal-Mag, how often should I use

Hi all, thanks for reading.

I started to use cal-mag in my nute tank, I am using RO water. With a tank change every 2 weeks, how often should it be added to the tank?

My concern, is that when I top off daily that I may need to add it between res. changes.


TIA

I add mine at rez changes but I change once a week as I find even with 10 to 15 gallon rez the ppms rise quickly at the end of the week late in flower. There are quite a few discussions on whether to add nutes or not when topping. Because after a week you don't know exactly which dissolved solids you are reading with your meter it is kinda hard to determine what they are lacking. So by adding, topping, off the rez with a mix nute solution that matches the original for that 2 week period you could be spiking one nute or another depending on what exactly that plants have been using the most and least of.
I know that they say the Iron in the cal/mg solutions falls out quickly and even more rapidly with magnetic pumps but with adequate rez circulation I wouldn't think this would be as big a problem.'

Out of curiosity how adding, mixing the cal/mg?

i use it at 5ml/gallon every nute change (every 5-7 days) i also use RO water.