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Soft Coral

Adding Green Star Polyps To Back Glass Wall

By March 3, 2023No Comments
green star polyp corals

Green Star Polyps are one of the most popular soft corals for beginners. While a lot of experienced reefers think they are a nuisance, they can be an attractive addition to your tank if done right.

One common way of adding Green Star Polyps is by attaching them to the glass or back wall in your aquarium. This will provide a focal point for your reef tank. You can have a beautiful carpet of green color swaying with the flow. This way you can enjoy a coral that you like it your tank, but you can manage it properly.

GSP grows fast and it cover everything that it touches. This is why a lot of reefers choose to put it on the back wall instead of their live rocks. If you add GSP to your rocks, they will overgrow everything and cover it all up.

How To Attach Green Star Polyps To Glass

The best way to add Green Star Polyps to glass is by using Cyanoacrylate (Super Glue.) You can either attach a small frag plug to the glass, and the GSP will grow over the plug and onto the glass. Or, you can attach a piece of it directly to the glass. This is the recommended way.

Green Star Polyp on glass
GSP Coral growing on glass (

Here are the steps:

  1. Take a piece of GSP or a frag and put glue on the bottom of it. The bottom will not have any green tentacles sticking out of it. Make sure to add the glue to the bottom.
  2. Hold the glued piece against the back wall for about 20-30 seconds. Once you remove your fingers, it should stay in place.
  3. Once stuck in place, the green star polyp will continue to grow all over your back wall or the glass.

An optional way to get GSP coral to grow on your back wall is to put a frag plug or a rock right next to the glass. Over time the coral may stretch out and start growing on your glass. They key word here is “may.” I have a rock covered in GSP and it has never attached itself to the glass. The rock is right next to the back wall. Others, have had success doing it this way though. My recommendation is to use super glue if you want it to start growing and spreading there immediately.

Below, you can see a picture of a GSP frag connecting itself to the back wall and growing. At this point you could keep the frag there, or you could cut it and move it somewhere else. The purple mat that is attached to the glass will stay there and grow.

GSP coral growing on back wall

Best Place To Put GSP On The Back Wall

Green Star Polyps like to grow in the direction of flow, and they like to grow up towards reef lights. Keep that in mind when you glue a piece to your glass. It should grow in any direction, but it will grow faster in the direction of flow. So, if your water flow is from right to left, then place your GSP at the bottom right of your tank. The GSP will then grow up and to the left.

This is best practice but it is not imperative. The GSP is going to grow all over assuming you have the enough nutrients and lighting.

Here is a video of a GSP coral growing up the back of the wall in a reef tank:

How To Remove Green Star Polyps From Glass

If you want to remove Green Star Polyps from glass you can use a sharp razor blade to scrape them off. Simply take a blade and slide it underneath the purple mat. Once you have a little piece removed from the glass, then you can take your fingers and peel a section off. You can also use a plastic card like a room key or credit card to get underneath it.

Here is a video demonstrating how to remove green star polyps from the wall of a reef tank:

This will become necessary over time as the GSP will continue to spread from your back glass to the sides of your tank. It will also cover anything that is connected to or touching the glass. Consistent pruning of this back will be necessary. This is why a lot of reef tank owners do not like GSP coral.

GSP coral should not grow from your back wall onto the sand bed. If it does, they are easy to remove and control.


GSP corals are great and easy to maintain. They make a nice splash of color to the back of your tank if you want go that way. For more information on how to care for GSP coral, we have a guide available.

These grow quickly in tanks with nitrates over 5 ppm along with proper lighting. In no time, you can have your entire back glass covered with GSP.


My name is James, and I am the founder of Saltwatercoraltank. I love everything about the ocean, and my main hobby is saltwater aquariums. Currently, I have 3 tanks that I maintain. I have a 130 gallon mixed as my main, and I prefer softies.

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