Latest articles

• Refugium in practice — structure, macroalgae and daily management

  The refugium's four biological functions, macroalgae species comparison, lighting, reverse cycle, trace element compensation, harvest schedule and comparison with Chaeto reactors.

  Practice

• Refugium — microfauna, trace element chemistry and biological balance

  Copepod ecology under predation pressure, macroalgae trace element mechanisms, DOC dynamics, the refugium's role in competitive ecology and the microbial loop.

  Deep dive

• The stability principle — why consistency beats perfection

  A single measurement vs. trend, the paradox of constant adjustment, one change at a time, and why predictability matters more than hitting a perfect target.

  Basics

• Carbon dosing research — biochemistry, the microbiome and open questions

  Two distinct biological mechanisms, DOC's effect on microbiome composition, biopellets and PHB, and the questions science cannot yet answer.

  Deep dive

• Dinoflagellates — ecology, toxins and biological control

  Why dinos are opportunists not invaders, Shewanella bacterium's algicidal activity, Dictyota allelopathy, ovatoxin biochemistry, cysts and why the biological control system collapses in aquariums.

  Deep dive

• Dinoflagellates in the aquarium — identification and treatment

  Species identification with a microscope, two treatment strategies (swimmer vs. sand dinos), UV sizing, silicate treatment, Ostreopsis safety warning and relapse risk.

  Practice

• pH in the reef aquarium — what it is and why it fluctuates

  The logarithmic scale, diel variation, safe range, indoor CO₂ as a hidden cause, and why an electrode is the only reliable measurement tool.

  Basics

• pH in practice — diagnosis, raising and management

  The air test, causes of low pH in order of frequency, all raising methods compared, electrode calibration, and a monitoring schedule.

  Practice

• pH research — carbonate chemistry, cellular regulation and nature's paradoxes

  The carbonate system's three forms, aragonite saturation state, the vital effect, the Bourake paradox, and ocean acidification in aquarium context.

  Deep dive

• Water flow in practice — pumps, placement and dead zones

  The turnover rate myth debunked, flow's five biological functions, species-specific needs, gyre setup, dead zone diagnosis and coral behaviour as a flow indicator.

  Practice

• The physics of water flow — from the boundary layer to cilia

  Diffusive boundary layer as a bottleneck, Shapiro 2014 ciliary paradigm, colony morphology as a flow modifier, gyre hydrodynamics and open research questions.

  Deep dive

• 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

• Allelopathy — chemical competition in a closed system

  Allelopathy in the reef aquarium: where it comes from, how it manifests, and how to manage it with activated carbon, ozone and placement.

  Practice

• Allelopathy — molecular-level chemical ecology

  The biochemistry of allelopathy: terpenoid structure, the cembranoid family, macroalgal isoprenoids and the mechanism of action at the coral cell level.

  Deep dive

• 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.

  Basics

• 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.

  Practice

• Iron and dinoflagellates

  Why the absolute level of iron is a misleading starting point for managing dinoflagellates — the competition model, biological mechanism and practical steps.

  Deep dive

• 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.

  Basics

• 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.

  Practice

• The microbiome as the tank's foundation

  What the microbiome is, what it does, how DOC and oxygen drive microbial balance — and why the hobbyist's daily choices affect it more than most realise.

  Practice

• Light is not set by eye — the PAR meter in practice

  What PAR and cPUR measure, why LED lighting requires measurement, species-specific reference values and the principles of light acclimatisation.

  Practice

• 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.

  Basics

• Phosphate deep dive — biochemistry, the skeleton and open questions

  Phosphate forms in water, phosphate as the cell's fundamental molecule, the one-way path into the skeleton, calcification inhibition biochemistry, particulate phosphate and Liebig vs. Redfield.

  Deep dive

• 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.

  Practice

• 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.

  Basics

• Flow is a biological necessity

  Why turnover rate is the wrong metric, how to measure flow velocity in cm/s, the gyre principle and species-specific flow requirements.

  Basics

• 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.

  Practice

• Cleanup crew — the right animals, the right time

  Selecting, sizing and timing the cleanup crew: snails, hermit crabs, urchins and sea stars in the reef aquarium.

  Practice

• The cycling process — what happens before adding any animals

  The basics of the nitrogen cycle, nitrification microbes and what actually happens biologically during the cycling phase.

  Basics

• The cycling process in practice — protocol, equipment and when the tank is ready

  Step-by-step cycling protocol: filling, seeding, monitoring, ICP test and equipment startup.

  Practice

• 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.

  Basics

• Zooplankton and phytoplankton — practical addition, dosing and maintenance

  Practical protocol for seeding, dosing and maintaining phytoplankton and copepods in the reef aquarium.

  Practice

• Zooplankton and phytoplankton in the reef aquarium — biological basis and ecological significance

  Plankton biology, copepod fatty acids, the microbial loop and the ecological significance of heterotrophy in the reef aquarium.

  Deep dive

• New approach — 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.

  Deep dive

• 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.

  Reference

• Saxby's principle — water comes first

  Why reefkeeping is not about keeping animals but about keeping water, and what this means in practice.

  Basics