If you ask ten saltwater hobbyists whether LPS and SPS corals should go together in one aquarium, you may get ten varied answers, for these types develop at different rates and feed and require varying amounts of space differently. Even so, they can share a tank. It just takes a bit of planning.
If you're putting together a mixed display, you've probably been scrolling through live corals for sale online already. Before anything goes in your basket, spend a few minutes thinking about compatibility. It costs far less than replacing a coral that's been stung by its neighbour.
What Makes LPS and SPS Corals So Different?
LPS means Large Polyp Stony corals. Imagine hammers, torches, euphyllias and brains. They have soft fleshy polyps and their growth rate is slow but stable, tolerating slight fluctuations in water parameters. That's why plenty of beginners start here. The catch is that all that soft tissue moves around in the flow, and a sweeping tentacle will happily sting anything within reach.
SPS stands for Small Polyp Stony coral and includes the corals that branch or plate such as Acropora, Montipora, and Stylophora. The polyps of these corals are small and hence need bright lighting and water flow instead of hand feeding. They grow quickly and colour up beautifully, but they're fussy. Any swing in calcium, alkalinity or light intensity shows up fast.
Why Does Placement Matter So Much in a Mixed Reef?
The majority of issues associated with a mixed tank begin with placement of the corals, rather than the condition of the water. Corals will protect their territory by means of sweeper tentacles, chemicals, and even simply overgrowing, so your initial setup can determine your future tank appearance. These habits help:
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Put LPS corals lower down, away from the strongest light and in gentler flow.
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Place SPS higher up, close to the lights, where the water movement is stronger and more turbulent.
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Leave wide gaps between colonies. LPS polyps stretch well past the edge of their skeleton.
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Keep aggressive LPS such as hammers and torches away from slow-growing SPS frags.
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Take another look at your spacing every few months, because both types keep growing and their reach changes.
Get this right early and you'll spend a lot less time cutting overgrown colonies apart later.
Can One Set of Water Parameters Suit Both Coral Types?
Mostly, yes, but it takes some compromise. SPS handle parameter drift badly. A tank set up purely for them, with rock-steady alkalinity and very low nutrients, can leave LPS looking pale and underfed, because LPS do better with a little more nutrient in the water and some direct feeding.
For most experienced reefers, compromise is found somewhere in the middle. Have your calcium, magnesium and alkalinity levels stable and within the parameters preferred by SPS, but have your nutrients on the high side of the acceptability threshold. SPS stay happy, and your LPS still get enough to keep their polyps plump and full. Test regularly. When you're balancing two sets of needs, frequent testing is how you catch a problem before the corals show it.
What Should You Check Before Choosing a Live Coral Retailer?
You can't inspect a coral in person when you order online, so it pays to do some homework first. If you've spotted some LPS corals for sale that you like the look of, run through this list before you check out:
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Look for photos showing the polyps fully open, not just a bare skeleton.
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See whether the seller gives clear advice on dipping and acclimatising corals once they arrive, since this takes a lot of stress out of delivery.
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Ensure that heat packs are supplied and next-day shipping is available when it is cold outside.
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Find out about the water conditions in which the coral currently lives to acclimate your tank slowly to match these conditions.
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Read reviews that are specifically about livestock, rather than feedback on dry goods or equipment.
The same checks apply when you're comparing an SPS coral for sale listing, because good photos and sensible shipping matter just as much for fast-growing SPS. UK sellers like Marine World Aquatics also stock feeding products for each coral type, including LPS-specific foods and SPS coral foods. That's usually a good sign the retailer understands reef keeping and isn't simply moving stock.
How Do You Introduce New Corals Without Starting a Turf War?
A new coral shouldn't go straight to its final spot, however tempting that is after waiting for the courier. Leave it isolated for two to four weeks. That way, you will have an opportunity to observe its reaction to the water and to identify possible parasites before you introduce it to your corals. It's a small delay that protects the whole tank.
When you have to put it into place, take your time and watch its behavior over the next couple of days. Remember that many sweeper tentacles appear during the night, so make sure to look into your tank after the lights are turned off and see who else is extending himself further than expected. Moving a coral a few centimetres in the first week is easy. Doing it after the colony has settled in and stung something is not.
Building a Balanced Mixed Reef the Right Way
Yes, LPS and SPS corals can definitely be in the same aquarium, but only through careful planning, and not merely by chance. You need to have a lighting gradient, varying flow rates between zones, and agree upon the right parameters for both before introducing the animals. A bit of patience at the start gives you a reef that actually thrives, instead of one where the colonies keep stinging each other or blocking each other's light.
If you're ready to start your own mixed reef, Marine World Aquatics offers a carefully chosen range for hobbyists at every level. Our corals and invertebrates sit alongside specialist feeding products, including LPS and SPS coral foods, and every order comes with a 14-day satisfaction guarantee and UK-wide livestock delivery. It's a straightforward place to browse live corals for sale online with confidence in the quality and the aftercare.
Ready to plan your mixed reef? Visit us to explore our coral collection and feeding range, and get expert guidance before your next livestock order.
FAQs
How long should I quarantine a new coral before adding it to a mixed LPS and SPS tank?
Two to four weeks suits most corals. That's long enough to spot pests such as flatworms or nudibranchs before they reach your main display. SPS are worth watching for a bit longer, because early bleaching or tissue recession is easy to miss if you rush the introduction.
Why does my SPS coral look fine while my LPS won't open fully in the same tank?
It usually points to a nutrient or flow problem rather than anything serious. LPS often need slightly more nutrients and more direct feeding than a tank tuned only for SPS growth. Offering a dedicated LPS food a few times a week often fixes it.
Is it normal for corals to sting each other without touching?
Yes, and it's one of the most overlooked causes of stress in mixed tanks. Many LPS species put out sweeper tentacles at night that can reach several inches past their base, so spacing has to allow for that, not just for the coral's daytime size.
Do I need two separate lighting zones for a mixed reef?
Not two fixtures, no, but you do need a clear gradient of light within the one tank. Put SPS higher up, near the lights, and LPS lower down where the intensity drops off naturally. That normally does the job without any extra equipment.
What's the biggest mistake beginners make when combining LPS and SPS?
Rushing the layout before they understand how each coral grows. What appears to be a well-spaced frag right now might be completely full of growth in a couple of months, so be sure to plan according to how big your colony will grow.
