Routine guide / UK

A reef water testing schedule that scales

A schedule is a starting template, not a law of reef biology. Test more often when the tank is changing, dosing is new or a result is surprising; test less often only after the trend is understood.

Three useful phases

Tank phaseStarting cadenceMeasure firstWhy it changes
Fishless cycle / new biofilterAmmonia and nitrite daily or whenever an input changes; nitrate every few daysAmmonia, nitrite, nitrate, pHYou are watching a moving process, so sparse snapshots can miss the transition
Newly stocked systemAmmonia and nitrite after additions; nitrate and alkalinity weeklyAmmonia, nitrite, nitrate, alkalinityBioload, saltwater changes and early maintenance are still settling
Established mixed reefSalinity and temperature at each maintenance; alkalinity weekly or more often when dosing; calcium, magnesium, nitrate and phosphate weekly to fortnightlyAlkalinity, calcium, nitrate, phosphateConsumption and nutrient export—not the calendar alone—set the useful frequency

Make the result comparable

Test at a similar time, before or after maintenance in the same way, and rinse vials with the sample where the instructions allow. Record the exact result, units, kit and date. If you change salt, dosing, feeding and filtration at once, you lose the ability to learn which change mattered.

When to increase frequency

  • You start or change a dosing pump.
  • New coral, fish or a large clean-up crew changes demand.
  • Alkalinity, nitrate or phosphate moves faster than your normal trend.
  • A water change, equipment fault or contamination event may have altered the system.

When not to overreact

A single result can be wrong, mistimed or outside the method’s useful resolution. Repeat a surprising reading with clean equipment, check the reagent expiry and compare it with salinity and recent maintenance notes. Stability is usually a better objective than forcing a number back to an internet “ideal”.

Sources and limitations

Red Sea’s Marine Care documentation lists ammonia, nitrate, nitrite, pH and KH as separate tests with different ranges and test counts; that is why a new tank and a mature dosing system need different toolkits. This page does not prescribe livestock targets or replace manufacturer instructions.

INTERPRET THE NUMBERS

Start with nutrients and foundation parameters.

Choose the range and method that fit the question your tank is asking.

Compare nutrient test kits