Reef guides

In-depth articles on reef tanks: coral, water chemistry, lighting, and common problems.

Best Corals for Beginners: 15 Hardy Species to

Coral

Best Corals for Beginners: 15 Hardy Species to

Discover the best beginner corals for reef tanks. Covers the hardiest soft corals, LPS, and entry-level SPS with care requirements, placement tips, and what

Coral Bleaching Causes: Why Corals Turn White and

Coral

Coral Bleaching Causes: Why Corals Turn White and

Understand every cause of coral bleaching in reef aquariums. Covers temperature stress, light shock, chemical contamination, parameter swings, and the

Coral Growth Tips: How to Grow Corals Faster in

Coral

Coral Growth Tips: How to Grow Corals Faster in

Learn how to maximize coral growth in a reef aquarium. Covers the role of alkalinity, light, flow, feeding, nutrients, and stability in driving SPS, LPS, and

Coral PAR Levels: How Much Light Every Coral Type

Coral

Coral PAR Levels: How Much Light Every Coral Type

Learn the ideal PAR levels for SPS, LPS, and soft corals in reef tanks. Covers how to measure PAR, where light falls in your tank, and a complete PAR

Coral Placement Guide: Where to Put Every Type of

Coral

Coral Placement Guide: Where to Put Every Type of

Learn where to place SPS, LPS, and soft corals in your reef tank for optimal light, flow, and growth. Covers vertical zoning, aggression spacing, sand bed

LPS Coral Care: The Complete Guide to Keeping Large

Coral

LPS Coral Care: The Complete Guide to Keeping Large

Learn how to keep LPS corals healthy in a reef tank. Covers water parameters, lighting, flow, feeding, placement, aggression management, and the most common

Reef Coral Guide: Types, Care, Placement, and What

Coral

Reef Coral Guide: Types, Care, Placement, and What

Complete guide to reef tank corals. Covers soft corals, LPS, SPS, coral care requirements, placement strategy, feeding, fragging, and how to build a thriving

Reef Tank Guide: How to Set Up and Maintain a

Coral

Reef Tank Guide: How to Set Up and Maintain a

Complete guide to reef tank setup, maintenance, and long-term success. Covers water chemistry, lighting, coral selection, equipment, and the system-level

Soft Coral Guide: The Complete Care Guide for Reef

Coral

Soft Coral Guide: The Complete Care Guide for Reef

Learn how to keep soft corals healthy in a reef tank. Covers species profiles, lighting, flow, feeding, placement, chemical warfare, and why soft corals are

SPS Coral Care: The Complete Guide to Keeping Small

Coral

SPS Coral Care: The Complete Guide to Keeping Small

Learn how to keep SPS corals healthy in a reef tank. Covers water parameters, lighting, flow, feeding, acclimation, common problems, and the stability

SPS vs LPS Coral: Differences and Care

Coral

SPS vs LPS Coral: Differences and Care

Compare SPS and LPS corals for reef tanks. Learn how they differ in skeleton structure, lighting needs, flow requirements, water chemistry tolerance, and

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Lighting

PAR for Reef Tank: How Much Light Do Your Corals Need?

Learn what PAR is, how to measure it, what PAR levels different corals need, and how to use PAR readings to optimize coral placement and lighting in your reef tank.

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Lighting

Reef Tank Equipment Guide: Essential Gear for a

A complete guide to reef tank equipment covering lights, skimmers, return pumps, wavemakers, heaters, ATO systems, reactors, and controllers. What you need

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Lighting

Reef Lighting Complete Guide: Everything You Need

A complete guide to reef tank lighting covering PAR, spectrum, LED vs T5, photoperiod, coral placement, and how to choose the right light for your reef system.

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Lighting

Reef Lighting Guide: How to Choose and Set Up

A practical guide to choosing, mounting, and configuring reef tank lighting. Covers fixture selection, intensity settings, spectrum basics, and common setup

Algae in Reef Tanks: Why It Grows and What to Do

Problems

Algae in Reef Tanks: Why It Grows and What to Do

Algae in a reef tank is not random. Learn why different types appear, what they reveal about your system, and the proven strategies that eliminate them

Why Is My Coral Bleaching? Causes, Recovery, and

Problems

Why Is My Coral Bleaching? Causes, Recovery, and

Coral bleaching in reef tanks is rarely about one parameter. Learn the real causes, how to diagnose what triggered it, and what actually gives bleached coral

Why Does My Coral Die After Adding It? The

Problems

Why Does My Coral Die After Adding It? The

New coral dying within days of being added to your tank is rarely about water quality. Learn the real reasons corals fail after purchase, from acclimation

Why Is My Coral Not Opening? The Real Reasons

Problems

Why Is My Coral Not Opening? The Real Reasons

When coral polyps stay retracted, most reefers test parameters and find nothing wrong. Learn the real reasons corals refuse to open and how to identify the

Cyanobacteria in Reef Tank: Why It Keeps Coming

Problems

Cyanobacteria in Reef Tank: Why It Keeps Coming

Cyanobacteria in a reef tank is not an algae problem. It is a flow and organics problem. Learn why cyano appears, what it reveals about your system, and the

Dinoflagellates in Reef Tank: Why They Appear and

Problems

Dinoflagellates in Reef Tank: Why They Appear and

Dinoflagellates are the most frustrating outbreak in reef keeping. Learn why dinos thrive in clean tanks, how to identify the species you have, and the proven

High Nitrate in Reef Tank: Why It Climbs, What It

Problems

High Nitrate in Reef Tank: Why It Climbs, What It

High nitrate in a reef tank is a system imbalance, not a single mistake. Learn why nitrate accumulates, what levels actually harm coral, and how to reduce it

Low Alkalinity in Reef Tank: Why It Drops, What

Problems

Low Alkalinity in Reef Tank: Why It Drops, What

Low alkalinity is the most common cause of coral decline in reef tanks. Learn why alkalinity drops, how fast it can kill coral, and how to raise and stabilize

High Phosphate in Reef Tank: Why It Builds Up and

Problems

High Phosphate in Reef Tank: Why It Builds Up and

High phosphate in a reef tank inhibits coral growth and fuels algae, but crashing it to zero is worse. Learn where phosphate comes from, what levels actually

Reef Tank Crash: Causes and How to Stop It

Problems

Reef Tank Crash: Causes and How to Stop It

A reef tank crash can wipe out years of coral growth in hours. Learn the real causes of tank crashes, how to intervene during one, and how to rebuild your

Alkalinity in Reef Tanks Explained: Why It Matters

Water

Alkalinity in Reef Tanks Explained: Why It Matters

Understand alkalinity in reef aquariums. Learn what dKH means, why alkalinity is the most important parameter for coral growth, how to test and dose it, and

Calcium in Reef Tank: Why It Matters and How to

Water

Calcium in Reef Tank: Why It Matters and How to

Learn why calcium is essential in a reef tank, what levels to target, how corals use it, and how to dose correctly. A complete guide to reef calcium management.

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Water

How to Lower Phosphate in a Reef Tank: Proven

Learn how to lower phosphate in a reef tank using GFO, carbon dosing, water changes, and source reduction. Step-by-step guide to reducing phosphate safely

How to Raise Alkalinity in a Reef Tank: Safe

Water

How to Raise Alkalinity in a Reef Tank: Safe

Learn how to raise alkalinity in a reef tank safely using two-part dosing, kalkwasser, baking soda, or a calcium reactor. Step-by-step instructions for

Magnesium in Reef Tank: The Overlooked Key to

Water

Magnesium in Reef Tank: The Overlooked Key to

Learn why magnesium is essential in a reef tank, how it stabilizes calcium and alkalinity, what levels to target, and how to dose correctly.

Nitrate Levels in Reef Tank: What to Aim For and

Water

Nitrate Levels in Reef Tank: What to Aim For and

Learn what nitrate levels are ideal for a reef tank, why nitrate matters for coral health, and how to lower or raise nitrate for optimal reef chemistry.

Phosphate in Reef Tank: Target Levels, Testing, and

Water

Phosphate in Reef Tank: Target Levels, Testing, and

Learn why phosphate matters in a reef tank, what levels to target, how it affects coral health, and proven methods to lower or maintain phosphate for a

Reef Tank Parameter Chart: Complete Water Chemistry

Water

Reef Tank Parameter Chart: Complete Water Chemistry

A complete reef tank parameter chart with ideal ranges for salinity, calcium, alkalinity, magnesium, nitrate, phosphate, pH, temperature, and more. Quick

Reef Water Chemistry Guide: Every Parameter That

Water

Reef Water Chemistry Guide: Every Parameter That

The complete guide to reef tank water chemistry. Covers alkalinity, calcium, magnesium, salinity, nitrate, phosphate, pH, and how to maintain stable

Salinity in Reef Tanks: How to Measure and Maintain

Water

Salinity in Reef Tanks: How to Measure and Maintain

Learn what salinity is, why it matters in a reef tank, how to measure it accurately, and how to keep it stable. A complete guide to reef salinity and specific