In this article, I will provide you with suggested PAR values for given coral groups. At the outset, let me already point out that there is no one, perfect PAR for a given coral. This is a complex topic that requires a deeper dive. Before we start choosing the light strength for our corals, it is worth reading two related articles available on ReefPedia.
The first article is about the meaning of light in a marine aquarium. From it you will learn a lot about how to choose the right light for corals. The second article I recommend here is on what a coral needs to grow.
It’s worth reading both articles to understand what corals need to grow and how light works in a marine aquarium.
We must take into account the fact that if we want corals to grow quickly and look beautiful, light intensity, i.e. PAR, is only one of the elements. It is also worth noting that the coral is adaptive, so it will be able to grow in various conditions. However, if we want to give it a lot of light, we need to ensure strong circulation, which I wrote about in the article on light, mentioned above.
If we increase the light intensity because we bought stronger lighting or we move the coral from a tank with weaker lighting to an aquarium with stronger lighting, the corals should be acclimatized to light. If we have a new lamp that has such a possibility, we set the acclimatization and for a period of 2 weeks we increase the lighting power so that after this period we get the right power.
If we add a new coral, we put it lower and successively raise it on the rock so that it has more and more light.
PAR ranges for given corals
| Coral | Min PAR (µmol/m²/s) | Max PAR (µmol/m²/s) |
| Acropora | 200 | 550/700* |
| Cyphastrea | 100 | 200 |
| Discosoma | 50 | 150 |
| Goniopora | 100 | 300 |
| Euphyllia | 150 | 250 |
| Montipora | 100 | 400 |
| Pavona | 120 | 350 |
| Pocillopora | 150 | 400 |
| Chalice | 100 | 350 |
| Porites | 200 | 400/750** |
| Ricordea | 50 | 150 |
| Sarcophyton | 150 | 400 |
| Sinularia | 150 | 400 |
| Stylophora | 100 | 550 |
| Zoanthus | 80 | 150 |
*PAR 700 applies to selected Acropora corals and coral watching
**PAR 750 applies to Purites lutea
Summary
As I wrote above, there is no one perfect PAR for corals. On the one hand, the environmental conditions will allow the coral to be able to take up more energy from photosynthesis, on the other hand, the coral is adaptable and able to adapt to different conditions in a marine aquarium.
At this point, a great request to bear in mind what I wrote and treat the PAR values only as references, not determinants. In one tank such PAR will be better, and in the other it will be different. I suggest starting with a lower one and gradually increasing by observing.
About the author
Marek Protasewicz
Reefkeeping has been my passion for over 10 years now. I love learning. The hobby has taught me many valuable lessons, patience being the best example.
Combining work and passion is my path. I run Crazy Coral, a marine aquarium shop, for a number of years. Building this business from the scratch I learnt from my own mistakes at a heavy cost.
Later I managed a project aimed at development of methods for quick growth of Corals in non-natural conditions. The project was carried out by Get Sales, Poland.
Presently, I am responsible for distribution strategy at Reef Factory, of which I am a
co-founder. The company produces smart devices for marine aquaristics.
The last projects I have been involved in are Social Reef and ReefPedia.
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