Know your reef tank parameters at a glance with this expert-designed reference guide. From Professor Polyp — 10 pages of essential water chemistry knowledge condensed into an easy-to-follow format. Includes the popular Reef Water Chemistry Chart plus in-depth explanations. What's Inside: The Big 3 Relationship — Alkalinity, Calcium & Magnesium triangle diagram Full Parameter Range Chart — color-coded danger/caution/ideal zones for all critical parameters Professor Polyp's Chemistry Chart — the wall chart trusted by hobbyists and fish stores Testing Schedule — what to test and how often Emergency Response Cards — color-coded action plans for parameter crashes Troubleshooting Guide — common problems and fixes Parameters Covered: Alkalinity, Calcium, Magnesium, Salinity, Temperature, pH, Ammonia, Nitrite, Nitrate, Phosphate Format: 📄 High-resolution PDF (10 pages) — print it, laminate it, hang it next to your tank.