Use CalMag Alga when your aroids need stronger growth, better leaf development, and extra calcium and magnesium support.

This is especially relevant for Monstera, Anthurium, Philodendron, Alocasia and other fast-growing tropical houseplants. These plants often grow large leaves, thick petioles, strong stems and active root systems. That growth needs more than just nitrogen.

Calcium supports cell structure, root function, and stronger new growth. Magnesium is central to chlorophyll, which means it helps the plant keep leaves green and photosynthetically active.

CalMag Alga is most useful when your plants are growing fast, living under grow lights, planted in coco-heavy or very airy mixes, or watered with soft, filtered, RO, rain or low-mineral water.

Common signs where CalMag may help:

• New leaves coming out weak or distorted
• Pale new growth
• Interveinal yellowing
• Weak stems or soft growth
• Slow growth despite normal fertilizing
• Plants struggling in coco-heavy mixes
• Fast-growing plants that seem to “run out” of strength

Important: CalMag is useful when calcium or magnesium is actually missing. It is not the answer to every yellow leaf.

Mixing into substrate: Use 30-50 g per 10 L of substrate. Mix evenly into the substrate before potting. Best for fresh aroid mixes, coco-based mixes, and soil blends. For small indoor pots, start with the lower dose.

Watering: Use 5 g per 1 L of water. Mix well. Water the substrate from the top. Use once per week when the plant needs extra calcium and magnesium support.

For self-watering pots: Use it from the top through the substrate and replace the water from the reservoir with clean water. Do not pour the powder directly into the reservoir. Water it through the potting mix so it reaches the root zone without leaving unnecessary sediment in the water tank.

Foliar spray: Use 5 g per 1 L of water. Mix well. Spray leaves evenly. Use every 7-10 days if needed. Spray only when lights are off or weak. Do not spray under strong grow lights or direct sun.

Top dressing: Use 70-120 g per m² once per month. For houseplants, this is usually more relevant for large planters, plant walls, greenhouse tables or bigger containers. For normal indoor pots, watering or substrate mixing is usually easier to control.

Do not use it automatically on every plant. If your tap water is hard, or your fertilizer already contains enough calcium and magnesium, extra CalMag may not be needed.

Do not use it as a complete fertilizer. CalMag Alga supports calcium and magnesium levels, but your plants still need balanced nutrition.

Do not pour the powder directly into LECA, Pon, semi-hydro or hydroponic reservoirs. This is not a clean liquid hydroponic CalMag. It can leave residue, create sediment, and make reservoirs harder to keep clean.

Do not add it into moss poles. Moss poles are for aerial roots and humidity support, not for mineral feeding. Feed the root zone in the pot.

Do not use high doses in small indoor pots. Too much calcium and magnesium can compete with other nutrients and create imbalance.

Do not use it to fix root rot. Root rot is a watering, oxygen, substrate or hygiene problem. Fix the roots and substrate first.

Do not spray leaves in direct sun, under strong grow lights, or during the hottest part of the day.

Do not spray delicate new Alocasia or Anthurium leaves heavily. Young leaves can mark easily. Test lightly first.

Do not assume yellowing means CalMag deficiency. Yellowing can also come from pests, old leaves, low light, root damage, overwatering, underwatering, cold damage or lack of nitrogen.

Do not mix and store the solution for days. Mix what you need and use it fresh.

Do not expect damaged leaves to recover. Look at the next leaves. That is where improvement should show.

Not every plant needs extra CalMag. But when your Monstera, Alocasia, Anthurium or Philodendron is growing fast, under strong light, or in a low-mineral setup, it can make a real difference in the next leaves.