I've got six plants going in a flood and drain setup, two OG Kush, two White Widow, a Trainwreck and a G13 Haze. I noticed when I first put them in the bud room the WW started showing signs of calcium deficiency so I supplemented and they appeared to improve. I'm using General Hydroponics Flora series and the feeding chart recommends CalMag for only the first two weeks or so. Now I've noticed the same leaf appearance on one of my OG Kush plants. Have any of you found the need to supplement with CalMag further into the budding process? Is it safe for your plants if you to keep supplementing (according to instructions) longer into the budding tiimeline? I know that over-cheming anything can have disastrous results so I'm slow to go. How do you use CalMag?
I only use a cal-mag supplement when I grow in coco. This is because the coco will bond with calcium, making it unavailable to the plants. IF you over saturate it with a supplement until it can't take anymore, the calcium will once again be available to the plant. Any other method than that, I use a complete nutrient (GH Maxi series) which is quite liberal on the calcium compared to most. I don't feel like it's necessary to purchase incomplete nutrients with fancy labels, only to require my to purchase additional bottles of supplements. I suggest investigating a complete nutrient line that's best for you. Something else to keep in mind... different nutrients are available to the plant at specific pH levels. Calcium and Magnesium are more available at higher pH, like the other macro nutrients. If you run your pH low (like 5.5) you may want to try bumping it up to 6-6.5 where calcium and magnesium are more available to your plant. This would allow your plants to make better use of the nutrients that are already there. I would suggest doing this before adding supplements
Thanks OP...I set my fresh nutrients at around 5.8 and let them climb to 6.5 or so. I live on the Big Island of Hawaii and use "county water" which is basically big well water. Here, in this geography our ground water doesn't leach through layers of nutrient rich soil but just rock. It was suggested to me that our water lacks the elemental minerals that are common in water from most other regions because of this fact and that supplementing with calmag is neccessary. The more I asked around, the more people confirmed this hypothesis. I also learned that you can't really over do this particular supplement so I just today brought home a gallon of it and will add it in moderation to every feeding and every water top off till I stop seeing leaves go yellow on me. I'll of course, share my findings.