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Not pushing the tank cleaning product. I have neve used it.
Struvite is a phosphate mineral with formula: NH₄MgPO₄∑6H₂O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platey mica-like forms.
Solubility: Slightly soluble, dehydrates in dry, warm air
Crystal system: Orthorhombic crystal system
Crystal habit: Euhedral to platey
Crystal class: Pyramidal (mm2); H-M symbol: (mm2)
Formula (repeating unit): NH4MgPO4∑6H2O