Biobizz calmag is very strange, i didn't find right proportions or even result, when it was needed for healing not prevention.
Best product i used personally ( except Epsom salt for magnesium issues, in soil and tap water there should be plenty of calcium )
https://www.amazon.co.uk/TNC-CalMag-Treatment-Magnesium-deficiency/dp/B01H6ZG8I4
@LeroyDagobert91, if your kettle leaves anything on bottom after boiling, or grows up slowly, you have more than enough Calcium in water. Those who go through RO water has to add everything. You can find for most cities theirs water suppliers breakdown of what in what proportion is in theirs supplied water through pipes.
Edit : i loved biobizz line, still use soil and humus, but fish mix and calmag never had consistency in action, so i didn't use them ever.
@AsNoriu unfortunately amazon does not have an affiliate site in my country so I have a fairly limited product selection
so epsom salt and tap water can do the trick ? if calmag doesn't work i'll try that thanks :)