Hello, I am going to start my second grow [SIZE=14.3999996185303px](pure kush strain)[/SIZE] in soil (biobizz light mix) using biobizz grow,bloom and top-max. I had big problems with cal mag deficiency in first one while using RO water. My tap water is extremely hard PH 8.3 PPM 720 My RO water has same PH and PPM 120 because of mineralization addon that I have in my filter(but it didn't helped me with mag dif.). I ordered Grotek Cal-Max to prevent deficiencies. I also have molasses and epsom salt. My question is what is better to use pure RO water with cal-max according to grotek feeding chart, or mix it with my tap water and add a little bit cal-max? What are amounts of cal-max that I should use during grow? Thanks in advance.
I use biobizz soil and nutes, I'd do nothing more than adjust the pH on the tap water... http://forum.grasscity.com/indoor-grow-journals/1338224-first-photo-period-grow.html#entry20774636
I don't worry about ppm in my soil grows. The water here is quite hard though, 115mg/l total hardness. Most of the minerals present are a compounds of Calcium and Magnesium. By using RO water you are removing all of those minerals, and then suffering cal/mag deficiency in your plants... What's the point?
I found a very cheap source of mineral water so I think I will use it 405 ppm 7.0 ph minerals in milligrams Ca++ 80 Mg++ 16 K+ 13 Na+ 5 Cl- 170 SO4-- 18 HC03- 10 F- 0.3 what do you think?