Guides
Reef & saltwater guides
Honest, plainly-written guides and myth-busters — the depth behind the quick answers. Fact-checked against marine sources, never folklore.
All guides
Aquascaping a Reef Tank
How to aquascape a reef tank: build a stable, open rockwork that flows well and gives corals room to grow, with the principles and common mistakes.
Beating Reef Tank Algae and Pests
A calm guide to reef tank algae and pests: the new-tank uglies, cyano, dinos, hair algae and aiptasia - what causes them and how to beat them.
The Best Beginner Corals (and Why)
The best beginner corals: forgiving soft corals and a few easy LPS that tolerate modest light and stable water, with the honest caveat on each.
The Best Nano Reef Fish (Small & Peaceful)
The best nano reef fish: small, peaceful, reef-safe fish for tanks around 10-30 gallons, with honest tank sizes, jumper warnings and stocking caveats.
Reef Cleanup Crew: What Eats What
A reef cleanup crew guide: which snails, hermits, crabs and shrimp eat which algae and detritus, how many you need, and why overstocking starves them.
Coral Aggression and Placement
Coral aggression and placement: how corals fight with sweepers, stinging and chemical warfare, and how to space them so your reef stays peaceful.
Coral Care for Beginners
Coral care for beginners: keep soft corals, LPS and SPS in the right order - light, flow, placement, feeding and the water chemistry corals need.
Cyanobacteria (Red Slime): How to Fix It
How to get rid of cyanobacteria (red slime) in a reef tank: what it is, why it blooms (flow and nutrient balance), and the honest fix that lasts.
Dinoflagellates: How to Beat Dinos
How to beat dinoflagellates (dinos): why they bloom in zero-nutrient tanks, the counter-intuitive fix (feed the tank), and the full battle plan.
Do Clownfish Need an Anemone? Fact-Checked
Do clownfish need an anemone? No. Captive-bred clownfish thrive without one - here is the fact-check, and when an anemone is actually a good idea.
Dosing a Reef Tank: Alk, Calcium, Magnesium
Dosing a reef tank: when water changes stop being enough, how to dose alkalinity, calcium and magnesium safely, and the daily limits to respect.
Fish-Only (FOWLR) vs Reef Tank
FOWLR vs reef tank compared: cost, difficulty, lighting, chemistry and which fish you can keep - to help you choose your first saltwater setup.
How Much Does a Reef Tank Cost?
How much a reef tank really costs: the upfront gear, the ongoing running costs, and why a nano is not as cheap as it looks. An honest breakdown.
How to Acclimate New Fish and Corals
How to acclimate new fish, corals and inverts: the drip method step by step, why to match temperature and salinity, and never to pour in shop water.
How to Cycle a Saltwater Tank
How to cycle a saltwater tank: what the nitrogen cycle is, how to start it, how long it takes, and how to know when it is safe to add livestock.
How to Get Rid of Aiptasia
How to get rid of aiptasia in a reef tank: why crushing backfires, which predators actually work, how to inject them, and how to stop them coming back.
How to Get Rid of Bubble Algae (Valonia)
How to get rid of bubble algae (Valonia): the truth about popping it, whether emerald crabs work, safe manual removal, and how to stop it spreading.
How to Quarantine New Saltwater Fish
How to quarantine new saltwater fish: why a QT tank is the best habit in the hobby, how to set one up, how long to observe, and what to watch for.
How to Start a Saltwater Aquarium
How to start a saltwater aquarium the honest way: tank size, RO/DI water, cycling first, then fish and coral - a calm, no-panic beginner roadmap.
Is a Tang OK in a 55-Gallon or Nano Tank? Fact-Checked
Is a tang okay in a 55-gallon or nano tank? No. Tangs need about 6 feet of swimming room - here is the fact-check on tank size and ich.
Keeping Anemones with Clownfish
Keeping anemones with clownfish: why an anemone is an advanced, light-hungry animal, and how to give a bubble-tip the mature, stable tank it needs.
LED vs T5 Reef Lighting
LED vs T5 reef lighting compared: coverage, colour, cost, control and coral growth - the honest trade-offs, and why many keepers run a hybrid of both.
Marine Ich and Velvet: What to Do
Marine ich and velvet in reef fish: how to spot them, why quarantine is the real fix, and how they are treated - triage guidance, not a diagnosis.
Nano Reef vs Bigger Tank for Beginners
Nano reef vs a bigger tank for beginners: why small is cheaper but less stable, why bigger is more forgiving, and how to choose your first reef size.
New Tank Syndrome & the Ugly Stage
The reef tank ugly stage explained: diatoms, algae and cyano in a new saltwater tank, why it happens, how long it lasts, and why patience beats chasing it.
Ocellaris vs Percula Clownfish
Ocellaris vs percula clownfish: the false and true Nemo compared - size, markings, temperament and care - and which is the better first clownfish.
Preventing a Reef Tank Crash
Preventing a reef tank crash: why stability is everything, the alkalinity swings and neglect that cause crashes, and how to spot and stop RTN and STN.
Reef Tank Equipment: What You Actually Need
Reef tank equipment explained: what you actually need vs what can wait - skimmer, sump, return pump, powerheads, heater, RO/DI, ATO and controller.
Reef Lighting, Flow and PAR Explained
Reef lighting and flow explained: how much PAR soft corals, LPS and SPS want, how to acclimate light safely, and how much water flow a reef needs.
Reef Tank Water Chemistry Explained
Reef water chemistry made simple: salinity, alkalinity, calcium, magnesium, nitrate and phosphate - what to aim for and why stability matters most.
RODI Water for Reef Tanks (Why It Matters)
Why reef tanks use RODI water not tap: what tap water brings in (phosphate, nitrate, silicate, metals), how RO/DI works, and whether to buy or make it.
Saltwater Water Changes and Maintenance
Saltwater water changes and maintenance: why and how to change reef water, how often, matching salinity and temperature, and a simple weekly routine.
Should Reef Nitrate and Phosphate Be Zero?
Should nitrate and phosphate be zero in a reef tank? No - zero starves corals and feeds dinos. The modern target is low but not zero.
Soft vs LPS vs SPS Coral: Where to Start
Soft vs LPS vs SPS corals compared: light, flow, chemistry and difficulty for each group, and the order to keep them in as a beginner reefer.
Why Is My Coral Not Opening?
Why your coral is not opening: the real causes - flow, light, placement, alkalinity swings, pests and settling in - and how to work through them.
Your First Saltwater Fish
Choosing your first saltwater fish: the best beginner-friendly options, how many to add, quarantine, and how to acclimate them without shock.