How To Make Your Zoas Brighter

Did you purchase a Zoanthid coral which was bright and beautiful, but months later you find your Zoa polyps are losing their mesmerizing coloring? Or maybe it has arrived a little dull looking?

Zoas can be unpredictable…one day they are one color and the next they have morphed into another one. However, sometimes they start looking dull from poor conditions in your aquarium. So, what can be done to create a bright and healthy Zoa garden in your saltwater aquarium?

Ways To Brighten-up Your Zoanthid

Almost every hobbyist in the industry has asked how to make their corals brighter. Zoanthids, or Zoa for short, are a group of corals that offer diverse and bright color patterns to saltwater reef aquariums. 

With help from the big community we belong to, aquarium hobbyists from every inch of the earth have found that coloration is most affected by lighting. 

While more research is needed into how lighting affects pigmentation of corals in aquariums, what we do know is that Zoas’ bright colors will fade if they are unhealthy. 

Despite lighting being the most important factor in Zoa coloration, you should not forget other cofactors such as water flow, pH levels, alkalinity, and nutrient loading (feeding). However, when all those conditions are perfect, it is light that can make or break your Zoanthid’s colorful pigmentation. 

When your Zoa arrives you also need to be patient, you cannot expect them to show their best color range overnight. Much like when you move house and take time to settle in, so does your Zoanthid Coral. The shipping process can be very stressful for corals, therefore, always allow time for them to acclimate to their new home. 

You may also need to wait until your Zoa fully matures to appreciate their bright colors. Often as Zoanthids grow they appear duller. This is because they are using more energy for growth than their appearance. Do not worry, give them time to flourish fully and you will not be disappointed, trust me!

Zoanthids are pretty good at telling you if they are unhappy in their new home. If the lighting is too strong they will not fully open, and if it is too weak they will usually stretch their polyps towards the surface (or light fixture) to try and absorb more light energy. 

When your coral gains or loses coloration, the light energy can bend the pigment molecule inside your coral’s polyps. The light energy comes from lighting fixtures in aquariums as we cannot provide corals with the light energy directly from the sun.

Lighting For Brighter Zoas

Any light fixture can grow Zoanthid Corals, but deciding what lighting is best for you and your particular Zoa is difficult because every aquarium set-up is different, plus selecting lighting also depends on your budget. 

Many experienced zoanthid keepers use a combination of Metal Halide (14K is highly recommended) and LED light fixtures or T5’s with LEDs. Both these combinations will give your Zoa the best colors as long as your water parameters are stable, you have a good water flow and perform regular water changes. 

Ideal Water Parameters for Zoanthids 

*Always check the specific requirements for the species of Zoa you have as these are the general ranges for the whole Zoanthid group. 

  • Temperature: 75° – 80 °F
  • pH: 8.1 – 8.4
  • Salinity: 1.025 – 1.026
  • Alkalinity: 8 – 12 dKH
  • Nitrates: <10 ppm
  • Phosphates: <0.10 ppm
  • Calcium: 420 – 440 ppm
  • Magnesium: 1300 – 1450

To check your Zoa is getting enough lighting, it is recommended to invest in a Photosynthetic Available Radiation (PAR) meter. Attaching a PAR meter to your aquarium allows 24/7 monitoring, ensuring your Zoa maintains its brightness. This will also help you identify if you need to upgrade the bulbs in your lighting fixture. Be prepared to replace them every six to twelve months (depending on which lighting you use) to keep the best spectrum. 

If you decide to increase the light intensity inside your aquarium, remember to keep a close eye on the water temperature. Elevated water temperatures and too much lighting contribute to coral bleaching. However, as Zoanthids are not true corals (they are closely related to anemones), they seem to go darker or lighten up in response to extremely intense lighting conditions. 

If you are still unsure whether to increase the lighting in your aquarium, you can try slowly (and carefully) moving your Zoa further up the aquascape and see how they react over a couple of weeks or even months. 

Feeding For Best Coloration

What you feed your Zoa, can also influence their appearance. Feeding your Zoa with nutrient-rich foods such as Reef-Roids and Amino Acids (Elos Omega Amino Acids are great!) will benefit your coral’s health, however, be sure to remove any uneaten food, so your water chemistry is not affected.

Also dosing your aquarium water with trace elements such as iodine and strontium has also been known to help Zoanthids retain their bright colors. 


Increasing the light intensity, keeping water conditions stable, and feeding your Zoa with some tasty meals will make them brighter in no time!

  • Roy Lee

    I have an unhealthy obsession with reef keeping and maintaining successful tanks. If you haven't noticed from the website, I love everything related to saltwater tanks like coral, fish, and everything else in between.

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