Selecting Healthy Corals 🪸 What to Look for Before You Buy, and where?
|
|
Time to read 3 min
When you buy live coral online, there is more to consider than just whether it suits your tank or if you like the colour.
The health of the coral is one of the most important factors in long-term success. Selecting an unhealthy coral as a beginner is very easy to do, especially if you don’t know what signs to look for.
You can also check our website when you buy coral from us to check exactly the parameters on our tank that week to make sure you are organised for your new arrivals: click here
In writing this, I hope it helps you make better and more informed decisions the next time you are selecting corals for your reef aquarium.
Always Inspect the Coral Properly
When buying corals, always ask to inspect:
- The full coral structure
- The base of the coral
- The tissue condition front and back
Don’t be afraid to ask — as someone working in the aquarium industry, this is something I am always happy to do for customers.
A good coral inspection can often be the difference between long-term success and early failure.
Why Coral Source Quality Matters
The success of any coral heavily depends on the quality of the environment it has been kept in before purchase.
If a coral has been:
- Poorly maintained
- Kept in unstable water conditions
- Exposed to stress or injury
- Mishandled during collection or transport
…it will often struggle to recover, even in a perfect reef tank.
Starting with healthy corals gives you the highest possible chance of success.
Choosing a Good Local Fish Store (LFS)
Some quality local fish stores will mark corals as:
- NFS (Not For Sale)
This is done to:
- Allow recovery time
- Monitor coral health
- Ensure stability before sale
However, not all stores follow this practice, which is why choosing a reputable and honest LFS is extremely important in the reef hobby.
What to Watch Out For (Coral Health Warning Signs)
1. Tissue Recession
Look closely at the base of LPS corals such as Euphyllia species.
Signs include:
- Tissue pulling away from the skeleton
- Exposed skeleton near the base
- Shrinking or “melting” tissue
This can be an early sign of polyp bailout or stress response.
2. White Film or Mucus
After shipping stress, some corals may produce:
- Clear to white mucus coating
This can be normal initially, but:
- If it continues for more than 24 hours
- Or worsens over time
It is often a sign of an unhealthy coral.
3. Brown Jelly Disease
One of the most serious coral infections.
Signs include:
- Brown, slimy tissue decay
- Rapid tissue loss
- Exposed white skeleton
This is usually caused by protozoan and bacterial infections and is highly contagious.
⚠️ Never purchase corals showing brown jelly.
It can spread quickly to other corals in your aquarium and is extremely difficult to treat.
4. Skeleton Breaks & Damage
Many corals are fragged from larger colonies.
Generally:
- Clean breaks can heal successfully
- Straight, fresh cuts are ideal
Avoid corals with:
- Crushed skeletons
- Jagged or damaged bases
- Cracks extending into live tissue
These corals have a significantly lower survival rate.
5. Sulphur Smell / Dark Spots / Holes
A strong “rotten egg” smell or dark holes in skeleton may indicate:
- Dead internal sponge
- Borers (such as clams or worms)
- Internal decay within the skeleton
While some cases can be cleaned or treated, it is safer to avoid these corals unless you are confident they can be fully rehabilitated.
Coral Pests & Parasites
Always remember:
- Corals can carry pests and parasites
- Even healthy-looking corals may introduce unwanted hitchhikers
Because of this, it is strongly recommended to:
- Dip all corals after purchase
- Quarantine when possible
- Inspect closely before introducing to your display tank
For more information, refer to coral dipping guides (see related articles in this series).
Final Thoughts
Selecting healthy corals is one of the most important skills in reef keeping. Taking a few extra minutes to properly inspect a coral can save months of frustration and improve your long-term success rate dramatically.
Always prioritise:
- Clean tissue
- Stable appearance
- Good skeletal structure
- Reputable sourcing
Healthy corals = successful reef tanks.
