RecifAtHome guide
SPS (small-polyp stony corals) are the pinnacle of reefkeeping: fast growth, spectacular shapes and colours. They need a stable, mature aquarium. Here is how to get off to a good start.
In short
- Wait for a tank that is 6 to 12 months old with stable parameters.
- Start with Montipora, Pocillopora and Stylophora, then move on to Acropora.
- Strong light (200 to 400 µmol/m²/s) and powerful, variable flow.
- Aquacultured SPS are easier than wild-collected colonies.
When should you start keeping SPS?
SPS corals handle fluctuations poorly. Before adding them, the tank should be at least 6 to 12 months old, with healthy soft corals and LPS, and stable parameters for several weeks: alkalinity between 7 and 9 dKH with no sudden swings, calcium 400 to 450 mg/L, magnesium 1,250 to 1,400 mg/L, nitrate 2 to 10 mg/L and phosphate 0.02 to 0.08 mg/L.
Choosing your first SPS
| Genus | Difficulty | Notes |
|---|---|---|
| Montipora | Easy | Plating or branching forms, fast growth |
| Pocillopora | Easy | Very hardy, grows quickly |
| Stylophora | Easy to moderate | Thick branches, bright colours |
| Seriatopora | Moderate | Fine branches, fragile in transit |
| Acropora | Moderate to demanding | The most sought-after, sensitive to stability |
For Acropora, choose aquacultured colonies: our Acropora Signature Collection are grown in aquariums at our coral aquaculture facility, so they are already adapted to aquarium conditions. Mariculture Acropora, farmed in the sea, are acclimated at our facility before sale.
Lighting and flow
Aim for 200 to 400 µmol/m²/s PAR depending on the species: plating Montipora do well at 150 to 250, while Acropora prefer the upper part of the tank. Flow should be strong and variable: 30 to 50 times the tank volume per hour, with pumps on a wave programme to avoid dead spots.
Meeting calcium and alkalinity demand
An SPS tank consumes calcium and alkalinity quickly. Water changes are no longer enough: a dosing pump with Balling or all-in-one solutions, a calcium reactor or a hydroxide reactor ensures a steady supply. Test alkalinity at least twice a week.
Acclimation
- Equalise the temperature by floating the bag for 15 to 20 minutes.
- Dip the coral in a suitable pest treatment (coral care).
- Place the coral in the lower part of the tank, then move it up gradually over two to three weeks.
Pests and warning signs
- Acropora-eating flatworms: small and translucent, they leave feeding marks on branches. Inspect with a torch and treat the entire colony.
- Montipora-eating nudibranchs: they nibble the edges of the plates.
- Rapid tissue loss (white skeleton becoming visible at the base or tips): check alkalinity, temperature and salinity immediately.
White growth tips on an Acropora, however, are a good sign: they indicate active growth.
Frequently asked questions
Which SPS are best for beginners?
Montipora, Pocillopora and Stylophora: hardy and fast-growing, they are more forgiving than Acropora.
What alkalinity for SPS corals?
Between 7 and 9 dKH, and above all stable. Fluctuations of more than 1 dKH per day are one of the most common causes of tissue loss.
What lighting for SPS?
Strong reef lighting delivering 200 to 400 µmol/m²/s PAR where the corals sit.
Why is my Acropora losing colour?
Most often: a sudden lighting change, nutrients at zero or alkalinity swings. Check these three things before anything else.
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Guide written by the RecifAtHome team, coral aquaculture in Roche-lez-Beaupré (France) since 2010. Updated: October 2026.