Why does my Blue Raven Merletti Blastomussa Coral recede when I increase lighting?

B. merleti has small polyps that bleach and retract under high PAR. Aim for 50–120 PAR with blue-dominant spectrum and gentle, random flow. Sudden jumps in intensity can shock tissue; ramp up over 2–3 weeks. If edges thin or mouths gape, lower light or add shade. Moderate nutrients (NO3 5–15 ppm, PO4 0.03–0.1 ppm) help maintain color and tissue.

What feeding approach suits B. merleti’s smaller mouths?

Offer fine to small meaty foods 1–2 times weekly: enriched brine, small mysis, cyclops, or powdered reef foods. Target feed with pumps off for 10–15 minutes. Oversized prey is wasted and can foul water. Watch for feeder tentacle extension after lights dim; that’s a good window. Consistent micro-feeding supports polyp density and growth without nutrient spikes.

My colony stopped expanding after a neighbor LPS thrived—what’s happening?

B. merleti has short sweepers and loses turf wars against aggressive LPS and some soft corals. It’s sensitive to allelopathy and stings. Increase spacing, run fresh carbon, and adjust flow so no direct tentacle contact occurs at night. If tissue recession is localized toward the competitor, move the Blastomussa to a calmer zone with a buffer of at least 7–10 cm.

Why are inner polyps pale while outer branches look vibrant?

This species forms dense clusters on branching skeletons, and self-shading can starve inner heads of light and flow. Rotate the frag or adjust angle so interior polyps receive gentle light and indirect flow. Periodic target feeding of inner polyps helps. If the base is bare, consider trimming outer branches and remounting to open light paths and improve circulation.

Blue Raven Merletti Blastomussa Coral

Blastomussa

Overview

Blue Raven Merletti Blastomussa Coral shows small, tightly packed polyps forming round heads with contrasting centers. Blastomussa merleti is a fleshy, colonial large-polyp stony coral that does well under moderate light and gentle to moderate water flow. It is photosynthetic via symbiotic algae but accepts small meaty foods; occasional target feeding can support faster growth and deeper coloration. Place on stable rock with space around the colony, as sweeper tentacles can sting nearby corals.

Quick Facts

Care Easy

Lighting Low–Moderate

Flow Low–Moderate

Placement Low–Mid

Temperament Semi-aggressive (3–4 inches spacing)

Recommended Parameters

Temp 76–80°F

pH 8.1–8.4

Salinity 1.025–1.026

Calcium 400–450 ppm

AlkAlkalinity 8–10 dKH

Magnesium 1250–1350 ppm

Feeding photosynthetic, mysis shrimp, enriched brine shrimp, rotifers, copepods, cyclops, microplankton, coral-specific powdered foods, finely minced seafood, small LPS pellets

Care & Placement

Blue Raven Merletti Blastomussa Coral (Blastomussa merleti) prefers stable, clean water and gentle conditions. Provide low to moderate light (PAR ~50–100), acclimating to light slowly using screen or shaded placement for 1–2 weeks to avoid bleaching. Use low to moderate, indirect flow—enough to keep detritus from settling between heads but not so strong that flesh is pushed or torn. Feed 1–3 times weekly with small meaty foods (mysis, finely chopped shrimp, reef roids) by target feeding when feeder tentacles extend after lights down; this supports growth and richer coloration.Maintain temperature 76–79°F (24–26°C), pH 8.1–8.4, salinity 1.025–1.026 (35 ppt), calcium 400–450 ppm, alkalinity 8.0–9.5 dKH, magnesium 1300–1400 ppm. Keep nutrients modest and stable (nitrate 2–10 ppm, phosphate 0.03–0.10 ppm). Test weekly with reliable kits, use a refractometer for salinity, and avoid rapid swings—this species is sensitive to sudden changes, especially alkalinity and light. Place low to mid in the tank on sand or a stable rock ledge. Allow 2–3 inches of space; it’s generally peaceful with short sweepers but can be irritated by aggressive neighbors like Galaxea, Favia, and Hydnophora. Dip new pieces, inspect for pests, and drip acclimate. Tissue recession often points to too much flow, too little light, or unstable alkalinity; bleaching signals excess light. Address by adjusting placement, stabilizing parameters, and increasing gentle feeding.

FAQ

Frequently Asked Questions

About the Blue Raven Merletti Blastomussa Coral

Why does my Blue Raven Merletti Blastomussa Coral recede when I increase lighting?

B. merleti has small polyps that bleach and retract under high PAR. Aim for 50–120 PAR with blue-dominant spectrum and gentle, random flow. Sudden jumps in intensity can shock tissue; ramp up over 2–3 weeks. If edges thin or mouths gape, lower light or add shade. Moderate nutrients (NO3 5–15 ppm, PO4 0.03–0.1 ppm) help maintain color and tissue.
What feeding approach suits B. merleti’s smaller mouths?

Offer fine to small meaty foods 1–2 times weekly: enriched brine, small mysis, cyclops, or powdered reef foods. Target feed with pumps off for 10–15 minutes. Oversized prey is wasted and can foul water. Watch for feeder tentacle extension after lights dim; that’s a good window. Consistent micro-feeding supports polyp density and growth without nutrient spikes.
My colony stopped expanding after a neighbor LPS thrived—what’s happening?

B. merleti has short sweepers and loses turf wars against aggressive LPS and some soft corals. It’s sensitive to allelopathy and stings. Increase spacing, run fresh carbon, and adjust flow so no direct tentacle contact occurs at night. If tissue recession is localized toward the competitor, move the Blastomussa to a calmer zone with a buffer of at least 7–10 cm.
Why are inner polyps pale while outer branches look vibrant?

This species forms dense clusters on branching skeletons, and self-shading can starve inner heads of light and flow. Rotate the frag or adjust angle so interior polyps receive gentle light and indirect flow. Periodic target feeding of inner polyps helps. If the base is bare, consider trimming outer branches and remounting to open light paths and improve circulation.