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Chemistry Chemistry
pH
A measure of water acidity/alkalinity on a 0-14 scale - pH 7 is neutral, below is acidic, above is basic. Fundamental to fish comfort and biological processes.
Unit: pH Code: PH Scale: 0-14 logarithmic
📖 Overview
pH represents hydrogen ion concentration on a logarithmic scale, meaning pH 6 is 10x more acidic than pH 7. Different fish evolved in different pH ranges - Amazonian species in soft acidic water (pH 5-6.5), African Rift cichlids in hard alkaline water (pH 8-9), and reef inhabitants in stable buffered seawater (pH 8.1-8.4). Sudden pH shifts stress fish severely.
❓ Why It Matters
pH directly affects ammonia toxicity (higher pH = more toxic), gill function, ion uptake, and enzyme activity. Sudden pH swings of even 0.3 units can trigger osmotic shock. Long-term pH mismatches with species requirements suppress immunity and reproduction.
🧪 Testing Methods
Liquid drop-test kits are more accurate than paper strips. Digital pH meters offer highest precision but require calibration. Test at the same time daily - pH swings between day and night in planted tanks.
📈 How to Raise
Crushed coral or aragonite substrate. Baking soda (sodium bicarbonate) for temporary boost. Increase aeration to drive off CO2. Add carbonate hardness (KH) buffers.
📉 How to Lower
Peat moss in filter. Driftwood (releases tannins). Botanicals (Indian almond leaves, alder cones). CO2 injection (temporary). Reverse osmosis water. Dedicated pH-down products.
⚠️ Symptoms of Imbalance
Rapid gill movement (piping), hanging at surface, refusing food, clamped fins, sudden death. Ammonia burn intensifies in high pH.