Does APT contain copper?Updated 2 months ago

Yes, APT contains copper in tiny, chelated form.

But isn’t copper harmful? 

Copper is actually an essential micronutrient for both plants and shrimp - no plant will exist in an ecosystem without trace amounts of copper. Copper (Cu) is a micronutrient that is only needed in trace amounts, but is involved in several key plant activities, including photosynthesis, nitrogen utilisation, protein production and water regulation. Adequate copper is required for the formation of lignin, which affects the overall strength of the plant, and is critical for proper seed formation.  

Shrimp actually have copper-based blood, using the protein haemocyanin as part of their circulatory system (humans have iron-based haemoglobin instead). Copper is essential for shrimp and they get it from their diet. So while large amounts of copper are toxic to both plants and animals, small amounts are actually essential to both aquatic plants and shrimp. The dosage of copper in APT is carefully calibrated to be far from toxic concentrations, even if APT has been heavily overdosed.