Beginner’s Reef Guide

Welcome to Fab’s Reef – where we balance science with sarcasm and ocean life with office life. Use this guide to explore different tank sizes, compare FOWLR vs reef setups, and learn when to add corals.

Building a Reef in Your Living Room

Imagine compressing the Great Barrier Reef into a glass box in your home. Reef aquariums are mesmerizing — a swirling ecosystem of fish, corals and invertebrates — yet they’re also tiny chemical factories. Everything revolves around the nitrogen cycle: beneficial bacteria convert fish waste into less toxic compounds, and cycling a new tank typically takes between two and eight weeks. Patience isn’t just a virtue; it’s cheaper than replacing melted coral!

The volume of water influences everything from stability to stocking options. In a larger tank, waste is diluted and temperature fluctuations are slower, giving you time to fix issues before your clownfish stage a revolt. Smaller tanks are affordable and tempting but can be more difficult to stabilize; a single uneaten pellet can spike ammonia. Throughout this guide you’ll see why bigger tanks forgive more mistakes and why reef keeping rewards slow, deliberate choices.

We’ll also demystify the choice between FOWLR (Fish‑Only‑With‑Live‑Rock) and full reef setups, explain when to introduce corals, and provide comedic commentary to keep you smiling through algae blooms and water tests.

Nano (≤10 g)

Nano reefs are like espresso shots of the ocean – small, intense and unforgiving.

Pros

  • Affordable equipment and small footprint
  • Fits on a desk or small stand
  • Lower monthly consumption of salt and water

Cons

  • Chemistry swings rapidly; one misfeed can spike ammonia
  • Limited stocking – typically one or two tiny fish
  • Requires meticulous maintenance and frequent testing

Costs

Setup: $400–$700

Monthly: $15–$20

Suggested Livestock

  • Ocellaris clownfish
  • Clown goby or tailspot blenny
  • Firefish
  • Clean‑up crew (snails, hermits, shrimp)

Timeline

  • Cycle: 2–4 weeks
  • Add corals: After the tank cycles and algae blooms subside (~3–4 months)
  • Mature: 6–12 months

Small (10–19 g)

Small systems offer a bit more forgiveness but still require discipline.

Pros

  • Greater water volume slows down parameter swings
  • Room for a pair of clowns plus a goby or blenny
  • All‑in‑one kits make setup straightforward

Cons

  • Stocking options are still limited
  • Setup costs climb quickly
  • Water changes are larger and more laborious

Costs

Setup: $700–$1,200

Monthly: $20–$25

Suggested Livestock

  • Clownfish pair
  • Royal gramma or firefish
  • Watchman goby & pistol shrimp
  • Clean‑up crew

Timeline

  • Cycle: 2–4 weeks
  • Add corals: After the tank cycles and stabilises (~3–4 months)
  • Mature: 9–18 months

Medium (20–39 g)

Medium tanks hit the Goldilocks zone – forgiving yet manageable.

Pros

  • High water volume buffers against mistakes
  • Space for aquascaping and small schools of fish
  • Supports a variety of LPS corals later on

Cons

  • Higher initial cost for quality equipment
  • Larger water changes and more gear to monitor

Costs

Setup: $1,200–$2,000

Monthly: $25–$35

Suggested Livestock

  • Small school of chromis (3–6)
  • Starry or lawnmower blenny
  • Orange‑diamond goby
  • Clownfish pair and royal gramma
  • Clean‑up crew

Timeline

  • Cycle: 4–6 weeks
  • Add corals: Soft corals at 3–6 months; LPS corals at 6–12 months
  • Mature: 18–24 months

Large (40–74 g)

Large home reefs allow you to create dramatic rockwork and house semi‑aggressive fish.

Pros

  • Water parameters change slowly
  • More forgiving of overfeeding and minor mistakes
  • Supports tangs and dwarf angelfish

Cons

  • High startup cost and physical weight
  • Requires sturdy stand and larger water changes

Costs

Setup: $3,000–$4,500

Monthly: $35–$65

Suggested Livestock

  • School of chromis (5+)
  • Blenny and goby for algae and sand
  • Dwarf angelfish (e.g. flame or coral beauty)
  • Yellow, Kole or Tomini tang
  • Peaceful wrasses and cardinalfish

Timeline

  • Cycle: 4–8 weeks
  • Add corals: Soft corals at 3–6 months; LPS at 6–9 months; SPS after 12 months
  • Mature: 2 years+

Extra‑Large (75–149 g)

Extra‑large systems become showpieces with extreme stability and diverse stocking.

Pros

  • Very stable water chemistry
  • Large surface area for corals
  • Can house multiple tangs and reef‑safe predators

Cons

  • Expensive to set up and heavy
  • Requires reinforced furniture or flooring

Costs

Setup: $4,000–$7,000

Monthly: $50–$80

Suggested Livestock

  • Schools of chromis, cardinals or anthias
  • Dwarf angels and hawkfish
  • Multiple tangs (introduced carefully)
  • Wrasses and blennies
  • Clean‑up crew including conchs and cucumbers

Timeline

  • Cycle: 6–8 weeks
  • Add corals: Softies at 3–6 months; LPS at 6–9 months; SPS at 12–18 months
  • Mature: 2–3 years

Mega (150 g+)

Mega reefs are like ocean exhibits – stunning but require commitment.

Pros

  • Epic stability and aquascaping freedom
  • Can host multiple tangs and large angelfish
  • Becomes a living art piece

Cons

  • Very expensive and heavy
  • Requires structural reinforcement and large water changes
  • Complex equipment with higher running costs

Costs

Setup: $8,000–$15,000

Monthly: $80–$150

Suggested Livestock

  • Multiple tang species
  • Large angelfish and reef‑safe predators
  • Anthias schools and wrasses
  • Clean‑up crew with diverse inverts

Timeline

  • Cycle: 6–8+ weeks
  • Add corals: Begin softies around 4–6 months; LPS at 6–12 months; SPS after 12–18 months
  • Mature: 3+ years

FOWLR vs. Reef Tanks

Deciding between a FOWLR and a reef is like choosing between a burger and a gourmet salad. The burger (FOWLR) satisfies with less fuss; the salad (reef) dazzles with colour but requires prep. Here’s how they stack up:

Feature FOWLR Reef
Focus Fish + live rock Corals & invertebrates
Filtration Canister or simple sump; protein skimmer optional Skimmer, refugium, RO/DI; dosing for Ca/Alk/Mg
Lighting Low–moderate (1–2 W per gallon) High‑intensity spectrum
Water Parameters Nitrate <30 ppm; phosphate <1 ppm Nitrate <1 ppm; phosphate <0.2 ppm
Fish Options Wide (includes non‑reef‑safe species) Reef‑safe only
Cost & Complexity Lower setup & maintenance Higher; specialized equipment & supplements

Coral Timeline

Corals don’t appreciate being rushed. Follow this timeline to give them the best chance at thriving.

Months 0–2

Cycle the tank and let beneficial bacteria establish themselves. Keep fish out, lights off and test water obsessively.

Months 2–3

The notorious ugly phase: diatoms, hair algae and cyano. It’s like puberty for aquariums – awkward but temporary. Still no corals.

Months 3–6

Add hardy soft corals such as zoanthids, mushrooms, leathers and xenia. They tolerate moderate swings and lower light.

Months 6–12

Introduce LPS corals like hammers and frogspawn. Begin dosing calcium and alkalinity if needed and upgrade lighting.

After 12 Months

Consider SPS corals like Acropora once your tank is stable and you’re comfortable with testing and dosing. Welcome to reef nerd territory!