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Why Your Green Star Polyps Is Dying!

Although green star polyps (GSPs) have faded in popularity over the last year or two, there are still a large number of people who keep green star polyps in their aquariums so we still see a large number of questions about caring for green star polyps each month.

One of the more common questions that we have seen people asking recently is if their green star polyps are dying and how they are able to correct the problem.

The three most common reasons that your green star polyps will start dying include problems with tank mate nipping or eating them, incorrect light intensity, and poor water parameters including water flow.

Green star polyps are surprisingly hardy once their conditions for growth are optimal and even a heavily deteriated green star polyps can fully recover within a short period of time.

Due to green star polyps being a very popular coral option a couple of years back, there have been a number of people producing green star polyps frags to sell that really aren’t healthy to start with.

Always make sure that you are getting a healthy green star polyps frag from the very start to give your new coral the best possible chances of survival from the very start.

The stronger green star polyps frags really are hardy as far as corals go and can often take a decent amount of punishment before they have serious issues and even then, they can have a high chance of making a full recovery.

How Do I Know if My Green Star Polyps Is Dying?

It is usually obvious that your green star polyps are dying as their color can fade rapidly, they generally look weak and have that deflated or melted look to them, and they can look flat more like a slime algae than a green star polyps when dying.

Many people initially think that less heads can mean that a green star polyp is dying but this is not always the case and a healthy green star polyp can have a surprisingly large number of heads nipped off or eaten by its tank mates without issue.

A green star polyp should always be fluid and be able to move with the water flow in a natural manner but in some situations when a green star polyp starts dying it can start to look brittle and ridgid and will not move fluididly in the water with the flow.

Thankfully, this is one of the earlier signs that your green star polyp may be dying and offers you plenty of time to investigate the potential problems in your aquarium to find and fix the problem.

In some very rare situations, a green star polyp can detatch from the surface that it was seated to unless it is using glue or a permanent frag plate.

This is not usually a sign of the green star polyp dying but more of an indication that there is a problem in the area that you initially sat it with the water flow, light intensity, or temperature not being optimal for the green star polyp and it is trying its best to move to a different area of the tank.

How Fast Should A Green Star Polyps Grow?

Depending on the conditions in your aquarium, a healthy green star polyp should be growing at between half an inch and one inch per month with this being considered a healthy growth rate for most people.

In some situations, you can get a faster growth rate but this is not to be expected so don’t focus on the people on social media saying their green star polyp grows faster than yours.

Each tank is unique and has its own conditions that will effect the growth rates of your green star polyp and you have to factor this in.

Someone you may be seeing on social media saying that their green star polyp is growing at a rate of 1.5 inch per month may be keeping their green star polyp in a coral only tank that is fully optimised for green star polyp but you may be getting 0.5 inch of growth per month in a community fish tank where parameters are optimised for the fish.

As we touched on earlier in the article, there are some weaker green star polyp frag producers out there who prioritized volume of sales over health of the corals to try and capitalise on the boost in the popularity of green star polyps a couple of years back that can also effect growth rate.

Try to always stick with a heathy green star polyp if possible as it will not only have a better growth rate but it can also help the coral survive in harsher conditions.

What Kills Green Star Polyps?

Various species of crab and shrimp will kill and eat the heads of green star polyps in their tasks due to the coral being soft and packed with nutrition.

You can usually identify that a tank mate is eating the green star polyp as the head will have a clean cut from claws rather than just generally look weak as it will when the green star polyp is dying due to other causes.

Unlike harder corals, even some reef safe fish species have been known to kill and eat green star polyps in their aquarium but it does tend to be less common that it will be a fish eating the green star polyp.

You can usually get an indication if it is a fish eating your green star polyp due to the head having more of a stringy look to the break where the fish has removed it and the fibers are left exposed where as crabs and shrimp usually leave a clean cut.

Provided you notice the issue early enough, you can often quaranteen the offending tank mate or move your green star polyp to a new tank before it really starts dying and in most situations, it should make a full recovery.

As we touched on earlier, there have been a number of cases with green star polyp having a handful of heads left due to having issues only to make a full recovery over time once the are placed in an area with optimal conditions.

Do Green Star Polyps Like High Flow Water?

Green star polyps prefer areas of your tank with moderate to high water flow but in some situations they can live in areas with lower water flow but this is more challenging.

Problems with water flow levels in your tank is probably the most common reason that people end up having problems with their coral and their green star polyp dying.

Due to this, you should always plan out the placement of your green star polyps prior to putting them into your aquarium to try and match the coral up with the condition that it requires for optimal growth and to minimise the chances of the coral dying.

The majority of people will place their green star polyps in an area of their tank with moderate water flow as a moderate water flow level does tend to be much easier to balance for multiple other corals in your tank than high water flow.

This is where the planning stage of your green star polyp setup all comes into play as different setups may have to have the green star polyps placed in totally different areas due to having a range of corals that prefer different levels of water flow in the same tank.

Some people will simply stick to corals that all prefer moderate water flow though as it can make your life much easier in the long run and reduce the chances of you having problems with your coral dying in the future as you don’t have to worry about water flow problems.

Do Green Star Polyps Need Light?

A green star polyp will do well with low to moderate lighting and higher intensity lighting can result in problems with the green star polyp and eventually lead to serious issues that can cause the coral to start dying.

You should either use a lighting unit set to a low or medium setting ot place the green star polyp lower in your aquarium so the water is able to difuse the light for the GSP to thrive.

Light intensity is another very common problem that beginners to keeping corals often face as you have to balance the light intensity for all of the corals in your tank.

For the most part, a little prior planning will often be enough to prevent any problems with this but we do see people make the mistake of placing their green star polyp in an area of high intensity light to make it easier for them to view their coral.

Over time, high intensity light will start to take its toll on your green star polyp and can eventually cause it to start dying.

A green star polyp really doesn’t need much light and we have seen tank setups with very low light have their green star polyp thrive and grow at a rapid pace.


That brings our article going over why your green star polyps are dying and how you are able to fix the issue. Thankfully, unlike some of the other popular corals, green star polyps do tend to be a hardy coral and most people will be able to easily correct the problems causing their GSP to die and have it make a full and speedy recovery with minimal long term issues with their coral.