ReefDeck
Open the free logbook
ReefDeck
Open the free logbook
Practical, no-nonsense guides on the water chemistry and habits that keep a reef thriving — written by the team behind the free ReefDeck logbook.
The complete reference chart — salinity, alkalinity, calcium, magnesium, nutrients, pH and temperature — and why stability beats the perfect number.
How-toPer-parameter testing frequencies, explained — from the daily salinity glance to the twice-weekly alkalinity check, and why the schedule changes as your ta
GuideAn honest comparison of notebooks, spreadsheets and dedicated reef logbook apps — what each does well, where each falls down, and what to look for in any l
GuideA reading is a snapshot; a trend is a story. Learn to read slope, drift and consumption rates — and forecast when a value will leave your safe band before
TroubleshootingThe five causes of unstable dKH — and the practical steps to hold alkalinity rock-steady before corals bleach or stall.
GuideHow the big three interact, why magnesium is the anchor that keeps alk and calcium in solution, and what goes wrong when one drifts.
GuideHow alkalinity buffers pH, why CO₂ is the real driver of daily pH swings, and practical fixes when your pH refuses to rise.
How-toHow to measure your tank's true daily consumption, calculate the right dose from first principles, and ramp up safely without shocking corals.
GuideNot zero — just low. How to hold the right nitrate-to-phosphate ratio, spot symptoms of imbalance, and adjust both nutrients gently.
TroubleshootingBleaching, browning, or fading to pale pastels — each colour-loss pattern points to a different parameter cause. How to read the signs and where to look fi
TroubleshootingBrown, snotty strands that pearl off with bubbles — dinos thrive when nutrients are too low. Why they appear and how to recover without panicking.
How-toAmmonia to nitrite to nitrate — what actually happens during the cycle, the week-by-week timeline, how to test it, and when the tank is truly ready for liv
GuideICP-OES reports 30–70 elements at once. This guide shows you how to read the report, spot what matters, and avoid chasing every number.
GuideICP reveals what hobby kits miss — iodine, potassium, iron and more. Here is what each trace element does, what dangerous levels look like, and why less is
How-toYour Apex or GHL already logs temperature and pH every few minutes. Here is how to export that data and combine it with your manual tests for a complete, a
GuideWhat salinity and SG actually mean, why 1.025 is the modern target, and how to measure and hold it reliably.
GuideWhy any point in the 24–27 °C band is fine, swings are not, and how to detect drift early with logging.
How-toDaily glances, weekly tests and monthly deep-cleans — a realistic routine that keeps parameters steady and problems visible early.
How-toDated photos, placement notes and linked parameter logs — how tracking growth turns your reef into a long-term health record.
GuideWhat to test, how often, and how to turn raw readings into trends that actually protect your reef.