Nutrient excesses and deficiencies can be avoided by giving the right feed at the right time and by controlling the environment - EC, pH, temperature, humidity and light. Calcium and Magnesium problems often appear together in plants and most of the time can be easily fixed with the right dose of cal-mag.
Calcium is a secondary macronutrient that plays a big part in the structure of the plant, giving the cells more rigidity. A healthy cell wall means better nutrient uptake. It is also vital for healthy cell growth and division; without it, plant growth would be stunted. When using soil, it helps neutralising acids in soils, creating a good base for growing.
— Calcium Deficiency
Calcium deficiencies appear when the plant is not absorbing enough of it. This can have multiple causes, such as inadequate feeding or the plant being under stress. The most prominent sign is yellow-brown irregular spots on the leaves, especially young ones. The plant growth gets stunted, the flowers and vegetables grow very slowly, or stop growing at all. The leaves can be small and have a burned look: distorted with curling tips.
— Calcium Excess
Too much Calcium affects potassium, iron, magnesium and manganese uptake, so the plant will usually show signs of deficiencies of these elements. Also the plants growth gets stunted.
Magnesium is a secondary macronutrient fundamental for photosynthesis. The plant cannot take chlorophyll without magnesium. It also stabilizes the cell membranes and helps metabolism. It aids nutrient and carbohydrate absorption.
— Magnesium Deficiency
Magnesium deficiencies in plants are often related to acidic mediums (low pH) or excess of Potassium on the roots. It can be identified by spots on the leaves and the tips turning yellow. In-between the plant's veins can turn yellow. Leaves also have a tendency to dry and fall off, if not treated the plant can die.
— Magnesium Excess
The leaves turn to a dark-green shade. The plants growth gets stunted. Also the EC levels might be too high due to accumulation of salts, these being toxic to the plant.
■ HOW TO PREVENT IT
It can take some weeks for these issues to show signs, nothing is better than prevention! If you are growing in hydroponics or coco and your tap water has an EC level lower than 0.6 add Biogreen Calgel until the EC level is 0.6. If you are using soil, use Biogreen Calgel (per 1L of water): 0.25ml during the vegetation phase plus first week of flowering, 0.3ml on the 2nd and 3rd week of flowering, 0.35ml on the 4th and 5th week of flowering, 0.4ml on the 6th week of flowering, and finally 0.3ml after the 7th week of flowering.
■ HOW TO FIX IT
If your plant has signs of a deficiency already, flush your medium with pH neutral water for 2 days. Be careful with the EC levels of your tap water (hard water). If you are growing in hydroponics or coco and your tap water has an EC level lower than 0.6 add Biogreen Calgel until the EC level is 0.6. If you are using soil, use Biogreen Calgel (per 1L of water): 0.25ml during the vegetation phase plus first week of flowering, 0.3ml on the 2nd and 3rd week of flowering, 0.35ml on the 4th and 5th week of flowering, 0.4ml on the 6th week of flowering, and finally 0.3ml after the 7th week of flowering. Make sure your plant is in the correct environment and the right feeding regime is being followed (if using additional nutrients). Improvements should show on the new leaves after a week.
If your plant shows signs of excessive calcium or magnesium, flush it with just neutral pH water for one week. Return to the normal nutrient feed after that. If the plant doesn’t show improvement in one week, repeat the flush process.
Ultimately, it’s always better to prevent an excess or deficiency by guaranteeing that the plant is receiving the correct amount of nutrients. This can be done by following the feeding charts correctly, analysing the nutrient water levels frequently and maintaining the appropriate environment conditions.