Marine aquarists are very passionate about keeping corals in the aquarium. Beginner reef keepers or people who plan to have a first reef tank are generally recommended to start with soft corals, and then try to move on to keeping LPS corals. Advanced aquarists breed SPS, among which the largest group is formed by Acropora. But what are corals really and how do these groups differ from one another?
In this blog article you will read about different types of corals living in reef aquariums, e.g. sps corals, lps corals, soft and non-photo corals and how to choose right corals for reef building.
Table of Contents
What is a coral?
Before we start introducing you to the types of corals let’s start with the fact that corals are not plants, but animals. It’s worth remembering at the beginning. They live at shallow depths, where they form various, multi-colored colonies. They inhabit warm, well-lit and oxygenated coastal zones.
The diversity of corals is huge, so before placing them in the reef tank, it is worth understanding the differences and the requirements between the types of them so let’s read about it.
How many types of coral are there?
There are 4 main groups of corals, but we distinguish over 7,000 varieties of corals, so the variety is really huge:
- Soft coral – do not form a calcareous skeleton (Sarcophyton, Sinularia, Capnella, Ricordea, Zoanthus, Discosoma and many others),
- LPS corals (Large Polyp Stony corals) – corals forming hard skeletons with long polyps, small polyp stony coral (Goniopora, Euphyllia, Plerygora, Lobophyllia, Acanthastrea and many others),
- SPS corals (Small Polyp Stony corals) – hard corals with relatively short and small polyps (Acropora, Montipora, Stylopora, Seriatopora),
- NPS (non-photosynthetic corals) – they do not have zooxanthellae, i.e. symbiotic algae living in the coral tissue (Gorgonia, Menella). They feed on what they catch from the water.
What are soft corals?
Soft corals (also known as softies) do not have a calcareous skeleton and their polyps are fused together with tissue. Popular soft corals are easy to breed, and especially recommended for beginner aquarists. Softies are not sensitive to changes in water parameters, their maintenance is generally not difficult.
The most hardy soft corals are Sarcophyton, Sinularia and Discosoma. They don’t like too clean water and do well in a calm water current. Ricordea mushroom corals are initially a bit more difficult to maintain, but there are no problems with them in a mature tank. An interesting addition to your tank may also be a fluorescent Green Star Polyps coral (aka Daisy polyps or Starburst polyps). Lastly, if you choose to go with Zoanthus, it’s worth remembering that they like a slightly stronger, variable circulation. It will be good to make sure that there’s no dirt between their polyps.
What are LPS corals?
LPS corals are a little more difficult to keep by most reef keepers than soft corals. They require testing of water parameters and supplementation of macro- and micronutrients. Varieties, such as Scolymia, Catalaphyllia and even Euphylia, like to be fed.
When buying LPS coral, you should do the right research and understand the needs of each specific type. The difficulty of maintaining LPS in comparison to soft corals is that they require a specific approach to each species.
It’s very important to thoroughly understand the requirements of each LPS individually. You can find out more about the specific requirements of individual corals in our knowledge base – ReefPedia – here you will learn about corals and many other topics related to saltwater aquariums.
It’s also worth paying attention to the place where our coral is attached. LPS corals grow relatively quickly, which can lead them to “burn” other corals in the vicinity.
On the Internet you can find a lot of information that LPS corals are sensitive to parameter fluctuations, require bright lighting and good circulation. It is said that they are quite difficult corals. So I want to reiterate that each LPS coral has its own requirements. There are corals, such as Scolymia, that will like variable circulation, thanks to which Scolymia will be able to eat freely, but Euphyllia glabrescens, for example, likes the water to make its polyps move almost all the time.
When it comes to the lighting – corals like high-quality bright and moderate lighting because it provides them with the energy they require to live.
Are LPS corals sensitive to fluctuations in water parameters? Well, it depends. Let’s assume that all aquarists want to maintain stable water parameters. Nowadays, keeping the parameters at a constant level is quite simple. Several routines, possibly automation, should be introduced and we’re pretty much set.
What are SPS corals?
SPS corals are more difficult to maintain than the LPS. Here the difficulty is that we need a permanent environment with stable parameters. SPS coral is not forgiving of big mistakes. Acropora corals, which belong to the SPS group, may start to die if the KH level changes by 1 dKh per day.
If you are thinking about keeping SPS corals, I recommend starting with the easier ones, such as Seriatopra, Montipora or Pocillopora, which are a bit more forgiving than Acropora.
What do we need to take care of when thinking about SPS corals? Certainly a constant temperature, a stable level of macro- and micronutrients, low nutrients, good quality light, quite strong and variable circulation.
Non photosynthetic corals
This group lacks photosynthesizing zooxanthellae, therefore corals of this type feed heterotrophically and this is the greatest difficulty in maintaining them. They should be fed with frozen foods, phytoplankton and other foods.
Often, in the hands of first time reef keepers, they start to starve. Dendronephthya and Scleronephthya corals are more difficult, while Gorgons and Dendrophyllia are easier to keep in a reef tank.
What are other individual coral species?
Like we wrote above there are more then 7000 corals species. Here is the list of other individual coral species where you find some examples of them.
- finger leather corals
- grape corals
- ridge corals
- trumpet corals
- duncan corals
- bubble corals
- colt corals
- candy cane corals
The most populars for the beguines are: Sarcophyton, Discosoma, Sinularia and other softies.
Summary
Read more on our blog where you will also find information on different types of other corals and their requirements. We are constantly working and developing ReefPedia.org to provide you with reliable, verified information about saltwater aquariums.
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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