Why Is My Green Star Polyp Not Opening?

One of the most beautiful things about coral is their ability to open and close their mouths in response to various stimuli. This is used as a defense mechanism to eat food, expel waste, and regulate water flow.

When a coral doesn’t open its mouth, it can be a sign that something is wrong. In this article, we will explore some of the reasons why your green star polyp (GSP) coral may not be opening.

What is a Green Star Polyp coral?

Green Star Polyp is a type of coral that is known to be very hardy and easy to care for in the reef aquarium. It can be recognized by its bright green color and star-shaped polyps.

This coral is usually found in colonies and can grow quite large. It prefers moderate lighting and water movement and should be placed on the lower half of the aquarium. Green Star Polyp is a filter feeder and will need to be fed regularly with micro-plankton or other food supplements.

What are the signs that my Green Star Polyp is not opening?

One of the signs that your Green Star Polyp is not opening is if the coral tentacles are retracted and it is not extending them. If the mouth of the coral is not visible, this can also be a sign that it is not opening. Additionally, if the skeleton of the coral is visible, this is another sign that it is not opening.

What could be causing my Green Star Polyp coral not to open?

There are many reasons why a Green Star Polyp coral may not open.

  • One possibility is that the coral is not getting enough light. If the coral is located in a shaded area of the tank, it may not receive enough light to Photosynthesize and expand.
  • Another possibility is that the water quality is poor and the coral is not getting the nutrients it needs to thrive.
  • Finally, if there are too much algae in the tank, the coral may be overshadowed and will not open.

How can I help my Green Star Polyp coral open again?

Green Star Polyp (GSP) is a beautiful addition of coral to any saltwater aquarium, and they are relatively easy to care for. However, GSP can sometimes close up completely, seemingly refusing to open again.

If this happens, there are a few things you can do to help get your coral back to its usual self. One thing you can try is increasing the water flow in your tank. This will help keep the water moving around the coral and may help it to reopen. You can also try gently prodding the coral with a net or toothpick, sometimes this is enough to get it started opening again.

If these methods don’t work, you may need to take your GSP out of your tank and put it in a quarantine tank for a while. This will give it some time to relax and hopefully start opening up again.

How to tell if green star polyps are dead?

One question that often comes up is how to tell if a GSP is dead. The first thing to look for is whether the polyp is retracting into its skeleton. If the polyp is not retracting, then you can check to see if there is any color remaining in the coral.

If there is no color, then the coral is likely dead. Finally, you can check to see if the coral has any translucency. If it does not, then it is likely dead.

What is the best placement for green star polyp?

The green star polyp is a colorful and hardy coral that can be placed in a variety of locations in the reef aquarium. It prefers moderate to high light levels and moderate to strong water currents. The green star polyp is a good choice for placement in the upper half of the aquarium.

How long does it take for green star polyps to open?

GSP gets its common name from the small, green, star-shaped polyps that make up their colony. These polyps are usually retracted into the coral’s skeleton but will extend outwards to feed when they are provided with the right conditions.

GSP requires moderate to high lighting, moderate to strong water movement, and low to moderate levels of nutrients to open and thrive. In an aquarium with low light levels and weak water movement, GSP may never fully open. Conversely, in an aquarium with bright light and strong water movement, GSP may open quickly.


In conclusion, it is possible that there are several reasons why your green star polyp coral is not opening. One reason may be that the coral is not getting enough light. Another reason may be that the coral is not getting enough food.

You can try increasing the flow, the amount of light or food that the coral receives to see if that helps. If it does not, then you may need to get a new coral.