Blastomussa Coral Care Guide for Beginners
Learn how to care for blastomussa corals with proper lighting, flow, and placement. A practical guide to keeping blastos healthy and growing in reef aquariums.
Blastomussa coral is a fleshy LPS coral with round, swollen polyps that often look like small open discs or thick flower heads. Most pieces seen in reef tanks are blastomussa wellsi or blastomussa merletti, and both can bring strong color without needing intense light or heavy flow.
Blastomussa corals are usually kept for their full polyp shape, slower growth, and tolerance for calmer areas of the reef. Their appearance changes a lot based on light, flow, nutrients, and how settled the coral feels.
When blastomussa coral is happy, the polyps expand during the day and hold a soft, inflated look. When something is off, the tissue may stay tight against the skeleton, colors can fade, and feeding response may weaken.
Note: Blastomussa corals are not usually aggressive in the same way as many euphyllia or galaxea corals, but they still need space. Their fleshy tissue can be damaged if nearby corals sting them or if they are placed where they rub against rock.
Lighting Requirements
Blastomussa corals prefer low to moderate lighting in most reef tanks. They often come from shaded or lower-light areas, so strong reef lighting can cause the polyps to retract or lose color if the coral is moved too quickly.
A good starting point is a lower section of the tank or a partially shaded area. Once the colony remains full and stable, it can be adjusted slowly if more light is needed.
When light is too strong, blastomussa coral may stay tight, bleach, or develop a washed-out look. When light is too weak, it may survive but grow slowly and show duller color. Gradual changes matter more than chasing a perfect number.
Flow
Blastomussa corals generally prefer low to moderate flow. The flow should move across the polyps enough to keep debris from settling, but not so hard that the tissue folds, pulls back, or stays deflated.
When flow becomes too strong, polyps may retract and the fleshy tissue can rub against the sharp skeleton underneath. This is one of the common reasons a Blastomussa coral looks irritated even when water parameters seem fine.
Gentle, indirect flow usually works best. Acan corals and Blastomussa corals often like similar flow conditions, so areas that keep fleshy LPS corals open without blasting them are usually a good place to start.
Placement
Blastomussa coral usually does well on lower rockwork, shaded ledges, or the sandbed if the tank has stable conditions. It should be placed where the polyps can expand without touching rough rock or nearby corals.
Placement should also protect the coral from falling snails, shifting frags, and sand being blown onto the tissue. Sand sitting on inflated polyps can irritate the coral, especially if it happens often.
Once the colony settles and stays open for several weeks, it is better to leave it alone. Blastomussa corals tend to dislike constant moving, and repeated changes in light or flow can slow their recovery.
Aggression
Blastomussa coral is usually considered a lower-aggression LPS coral, but it is not defenseless. It can irritate nearby corals on contact, and nearby aggressive corals can damage it quickly.
The bigger risk is often damage from other LPS corals with longer sweepers. Hammer corals, torch corals, galaxea, and some favias can sting Blastomussa tissue if placed too close.
Give Blastomussa coral enough room to expand fully. In most cases, a few inches of space is safer than crowding it into a mixed coral garden where tissues touch at night.
Feeding
Blastomussa corals can survive mainly on light and nutrients in the water, but they often respond well to occasional feeding. The polyps can capture small meaty foods when their feeding tentacles are out.
Small foods work better than large chunks. Mysis, finely chopped seafood, reef roids, and other small coral foods can be offered gently near the mouth. If the food is too large, the coral may release it later instead of digesting it.
Feeding once or twice a week is usually enough in a stable tank. When nutrients are already high, heavy feeding can cause more problems than growth. The goal is a steady feeding response, not stuffing the coral.
Water Parameters
Recommended Water Parameters for Blastomussa Coral
| Parameter | Recommended Range |
|---|---|
|
76–80°F |
|
1.025–1.026 specific gravity |
|
8.0–8.4 |
|
8–9 dKH |
|
400–450 ppm |
|
1250–1400 ppm |
|
5–15 ppm |
|
0.03–0.10 ppm |
Blastomussa corals prefer stable reef parameters rather than constant correction. They can handle normal mixed-reef conditions, but sudden swings in alkalinity, salinity, or temperature often cause tissue recession.
Moderate nutrients are usually fine. Very low nutrients can make the coral look pale and slow to grow, while very high nutrients can encourage algae and bacterial issues around the skeleton.
Blastomussa Coral Growth and Spreading
Blastomussa coral grows slowly to moderately in most tanks. Blastomussa merletti usually develops new heads faster than Blastomussa wellsi, while wellsi often grows larger, fleshier polyps.
Growth often shows as new polyps forming around the base or between existing heads. Once the colony remains expanded, feeds well, and shows no tissue recession, new heads may begin to divide and develop.
Fragging should be done carefully because the fleshy tissue can tear easily. The safest approach is to cut through the skeleton between heads while avoiding the soft tissue as much as possible.
After fragging, the coral should be placed in low to moderate flow and lower light while it heals. Once the cut edges settle and the polyps expand again, the frag can be treated like a normal colony.
Frequently Asked Question
Yes, blastomussa coral can grow on the sandbed if the area has gentle flow and stable lighting. The main issue is keeping sand from collecting on the tissue. If sand builds up often, the coral may stay irritated.
Blastomussa coral is usually a good choice for newer reef keepers with stable tanks. It does not need intense lighting or strong flow. The tank still needs consistent salinity, alkalinity, and nutrients.
Blastomussa coral often stays closed because of strong light, strong flow, unstable parameters, or irritation from nearby corals. Check placement first, since too much direct flow can keep the polyps tight. Once the coral is moved to a calmer area, it may take several days to expand again.
Blastomussa coral does not need heavy feeding, but occasional small feedings can support growth. It usually captures food when the polyps are open and feeding tentacles are visible. Small foods are safer than large pieces.
It is better not to let blastomussa coral touch other corals. Its tissue is fleshy and can be damaged by stings or rubbing. Give it enough space to expand fully, especially in a mixed LPS tank.
Blastomussa coral usually grows slowly compared with faster LPS corals. Good stability, gentle flow, moderate nutrients, and occasional feeding can help it develop new heads. Growth is often gradual rather than explosive.
Tissue loss can come from parameter swings, physical damage, too much flow, coral stings, pests, or bacterial stress. Look for exposed skeleton, receding edges, and irritation near the base. Stable conditions and lower stress placement are usually the first steps.
