Soft vs LPS vs SPS Coral: Where to Start
🐠 The short version: corals come in three difficulty groups — soft (easiest) → LPS (intermediate) → SPS (advanced) — differing mainly in how much light, flow and chemistry stability they demand. Start with soft corals and easy LPS like duncans, and climb toward SPS only once your tank is mature and your parameters are rock-steady. Keep them in order and coral-keeping is far more forgiving.
🔧 Place any coral by its sourced light/flow needs on the coral placement guide, and get the full method in coral care for beginners.
Side by side
| Soft corals | LPS | SPS | |
|---|---|---|---|
| Skeleton | None (soft/fleshy) | Stony, large fleshy polyps | Stony, small polyps, branching |
| Difficulty | Easiest — start here | Intermediate | Advanced |
| Light | Low–moderate | Low–moderate | Moderate–high |
| Flow | Gentle–moderate | Gentle–moderate | Strong, turbulent |
| Chemistry | Undemanding (little alk/Ca draw) | Stable alk / Ca / Mg | Rock-steady alk / Ca / Mg, tested often |
| Feeding | Mostly light | Light + occasional target-feeding | Mostly light |
| Examples | Mushrooms, zoas, leathers, GSP | Hammer, torch, frogspawn, duncan, acan | Montipora, birdsnest, acropora |
| Main hazard | Some spread invasively; leather allelopathy | Sweeper tentacles (torch worst) | RTN/STN, pests, needs stability |
Soft corals — start here
No hard skeleton, low demands, and forgiving of lower light, gentler flow and imperfect water — ideal while you learn. Mushrooms, zoanthids, leathers and green star polyps. Two caveats: some (GSP, xenia) spread invasively and want their own rock, and zoanthids can carry palytoxin — handle with care. Browse the soft coral hub.
LPS — the next step
Large-polyp stony corals build a skeleton, so they start needing stable alkalinity, calcium and magnesium. Hammer, torch, frogspawn, duncan and acan. Duncan is the standout beginner LPS — peaceful and feed-loving. Many LPS have sweeper tentacles (torch is the most aggressive, out-stinging even other Euphyllia), so give them room — see coral aggression & placement. The LPS hub has the lineup.
SPS — the advanced end
Small-polyp stony corals are the compact, branching corals most people picture on a high-end reef. They demand high light, strong turbulent flow, and rock-steady chemistry, and they punish instability with rapid or slow tissue necrosis (RTN/STN). Montipora is the gateway, birdsnest the easiest branching SPS, and acropora the endgame — not a starter. Only climb here once your tank is mature and you already hold parameters steady (SPS hub).
Chemistry and dosing scale with the group
This is the thread through all three: as you move up the ladder, chemistry stability matters more. Soft corals ride on water changes; growing LPS and SPS consume alkalinity, calcium and magnesium faster, so you start dosing to hold them steady. Whatever you keep, nutrients stay low but not zero (why).
Which should you keep?
- New to coral? Soft corals + a duncan or two. Forgiving, colourful, rewarding.
- Comfortable and stable? Add more LPS, then dip into gateway SPS like montipora.
- Experienced, rock-steady tank? The full SPS world, acropora included.
A mixed reef of all three is achievable — you just cater to the most demanding coral for light, flow and chemistry, and place each in its zone while managing aggression.
The honest takeaway
The groups aren’t better or worse, they’re a difficulty ladder. Start soft, earn LPS, and reach for SPS only when your tank proves it can hold steady. Keep them in order and you skip the most common coral heartbreak.
Sources & further reading
- Coralkin — Coral care for beginners and the placement guide.
- Coralkin — Coral aggression & placement and Dosing a reef tank.
- Coralkin — Soft / LPS / SPS hubs — every coral we cover, difficulty-rated.
- Tidal Gardens, Bulk Reef Supply & WetWebMedia — coral husbandry references (per our care sheets).
Common questions
What is the difference between soft, LPS and SPS corals?
Soft corals (like mushrooms, zoas and leathers) have no hard skeleton and are the most forgiving. LPS (large-polyp stony, like hammer, torch and duncan) build a stony skeleton with fleshy polyps and need stable alkalinity, calcium and magnesium. SPS (small-polyp stony, like montipora and acropora) are compact branching stony corals that demand high light, strong flow and rock-steady chemistry - the advanced end.
Which corals should a beginner start with?
Soft corals and easy LPS such as duncans. They tolerate lower light, gentler flow and imperfect chemistry while you learn. Save SPS - especially acropora - until your tank is mature and stable, because they punish swings hard.
Do soft corals need dosing?
Usually not. Soft corals have little demand for alkalinity and calcium, so regular water changes typically keep them supplied. Dosing becomes necessary as stony corals (LPS and especially SPS) grow and consume those minerals faster than water changes replace them.
Why are SPS corals so much harder?
They need high light, strong turbulent flow, and very stable alkalinity, calcium and magnesium - and they react to instability with rapid tissue loss (RTN/STN). They also want a mature tank with low-but-not-zero nutrients. None of it is impossible, but it demands a keeper who already holds their parameters steady.
Can I keep soft, LPS and SPS in the same tank?
Yes, many mixed reefs do - but you cater to the most demanding coral (usually SPS) for light, flow and chemistry, and you place each coral in its preferred zone. You also manage aggression, since these groups include sweeper-stinging and chemically-warring species.
📚 More corals guides
🎓 Ready to go deeper?
Past the basics — same plain, no-panic voice, no ceiling: