Articles tagged: water chemistry
- Deep dive
Limewater (Kalkwasser) — chemistry and use
A deep dive into the chemistry of limewater: calcium hydroxide solubility, simultaneous Ca/ALK/pH support, the capacity ceiling, vinegar boosting, integrating trace elements, and modern safe dosing.
- Deep dive
Trace elements, macro-nutrients and micro-nutrients in the reef aquarium
A comprehensive guide to all ICP-OES element groups — macroelements, dynamic elements and the relevance line explained in practical terms.
- Basics
Water Changes — Why You Change Water
What accumulates and depletes in a closed reef system, why regular water changes are the most reliable maintenance tool, and what they cannot replace.
- Basics
Alkalinity — the buffer beneath the surface
What alkalinity is, why it depletes, reference values by tank type, measurement methods and supplementation from kalkwasser to calcium reactors.
- Basics
Calcium — the skeleton's building block
What corals are built from, why calcium depletes, magnesium's role in the calcium system and what happens when calcium drops too low.
- Practice
Calcium in practice — measurement, target values and dosing
Target values by tank type, the calcium-alkalinity relationship, measurement methods, dosing options compared and signs of imbalance.
- Basics
Magnesium — the invisible stability mechanism
Why seawater contains so much magnesium, its role in aragonite crystallisation and calcium solubility, and how its depletion shows up in the tank.
- Practice
Magnesium in practice — measurement, target values and dosing
Target values by tank type, why magnesium falls, dosing and correction, and signs of problems and impure salts.
- Basics
Phosphate — the first thing a new hobbyist should measure
What happens when phosphate is absent, what happens when there is too much, the target range, measurement methods and three rules to remember.
- Practice
Phosphate in practice — measurement, target values, management
Target values by tank type, N:P ratio, GFO trace element removal data, raising and lowering phosphate, and the zero-zero trap from a phosphate perspective.
- Basics
RO/DI — the foundation of clean water
What Finnish tap water contains, why zero TDS does not mean clean water, how an RO/DI unit works and where its limits lie.
- Practice
The big three in practice — measurement, target values and balance
The interdependence of alkalinity, calcium and magnesium, target values by tank type, measurement methods and signs of imbalance.
- Basics
Trace elements in the reef aquarium — why they matter
The biological role of trace elements, the most important ones, and ICP-based dosing in the reef aquarium.
- Deep dive
Ammonium and urea as nitrogen sources
The biological advantages of ammonium and urea as nitrogen sources for corals, the scientific research base and EU-market products in spring 2026.
- Reference
Nitrate — the other half of the nutrient pair
Nitrate's role in the nitrogen cycle, reference values by tank type, managing the nutrient pair and avoiding the 0/0 trap.
- Basics
Saxby's principle — water comes first
Why reefkeeping is not about keeping animals but about keeping water, and what this means in practice.