Dialing in mixed reef coral placement is one of the biggest keys to a healthy, visually balanced aquarium. When SPS, LPS, and soft corals are all sharing the same glass box, smart positioning can mean the difference between slow decline and explosive growth. Let’s walk through how to place each type so they thrive instead of fight.

Start With Your Light and Flow Map

Before adding any coral, take a few minutes to understand your tank’s light and flow zones. This makes later adjustments easier and prevents constant moving.

  • Top third: Highest PAR, strongest flow – best for most SPS and some high-light LPS.
  • Middle: Moderate PAR, moderate flow – ideal for many LPS and hardy SPS.
  • Bottom and shaded spots: Lower PAR, gentler flow – perfect for soft corals and low-light LPS.

If you’re unsure of your light levels, use the guidelines in our reef lighting guide and adjust based on coral response: color, polyp extension, and growth.

Placing SPS, LPS, and Soft Corals Together

SPS Corals: Top Real Estate

SPS demand strong, stable light and brisk, random flow. Place them high on the rockwork where they can receive:

  • Consistent PAR and minimal shading from other colonies.
  • Enough flow to keep detritus off the tissue without blasting the polyps.

Give branching and plating species extra room to grow upward and outward. Avoid putting delicate SPS directly down-current from aggressive LPS sweepers.

LPS Corals: Middle Ground Powerhouses

LPS corals are usually the troublemakers in terms of aggression. Many send out long sweeper tentacles at night and can sting neighbors several inches away.

  • Place them in the mid-levels with moderate, indirect flow.
  • Leave at least 3–5 inches of space between aggressive species and anything delicate.
  • Keep fleshy corals off sharp rock points to avoid tissue damage.

Tip: Watch your tank 1–2 hours after lights out once a week. Nighttime sweepers will show you which corals need more space.

For more spacing ideas, check out our LPS coral care basics article.

Soft Corals: Fill the Gaps

Soft corals tolerate lower light, variable flow, and can be excellent space fillers. Use them to create movement in areas where SPS and LPS won’t thrive:

  • Place them lower in the tank or in partial shade.
  • Use them along the sand–rock border to soften hard lines.
  • Keep fast-spreading species isolated on their own rock “islands.”

Just remember that many soft corals release chemical defenses. Running carbon and following the recommendations in our mixed reef setup guide helps keep the peace.

Balance, Maintenance, and Long-Term Planning

Great mixed reef coral placement isn’t just about today; it’s about how colonies will look 6–18 months from now. Plan for future growth:

  • Leave vertical space above SPS for branching and plating.
  • Allow LPS room to expand two to three times their current size.
  • Use fast-growing soft corals to frame, not smother, slower-growing species.

Revisit your layout every few months. If you see chronic stinging, recession on one side of a colony, or constant shading, it’s time for a small rearrangement. Thoughtful placement now means less coral loss and a far more natural, layered reef look over time.

By mapping light and flow, understanding aggression, and planning for growth, you can create a balanced mixed reef where SPS, LPS, and soft corals not only survive together, but truly thrive.

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