The_420answered grow question 6y ago Hello,
I would say it's because of the calcium, but if I were you, I wouldn't worry.
Prevention
• Add dolomite/lime to your growing substrate.
• A pH of 6.2 will provide a better environment for calcium absorption.
• Add lots of eggshells to your organic compost.
• Start a worm farm! Vermicompost offers a ton of nutrients, including calcium.
Solutions
• Apply a cal-mag booster.
• Increase or decrease the pH to reach 6.2.
• Add a teaspoon of hydrated lime to 4 liters of water and use the solution to water your plants.
I hope this helps you! 😉