There are two basic types of coral; hard coral and soft coral. Within the hard coral there are two sub categories; LPS and SPS. Soft coral are typically fast growing, relatively hearty and they grow on rock. Soft coral will not have an exoskeleton. LPS or large polyp stony corals will have an exoskeleton, they are slower in growth rate compared to soft corals, and they do have a skeletal structure which requires calcium carbonate for growth. SPS or small polyp stony coral also has a skeletal structure with smaller polyps or mouth’s within the colony. SPS coral can be slightly faster in growth rate compared to LPS and are less forgiving when it comes to chemistry swings in the water.
So when asking what the requirements for coral are, we need to ask ourselves what coral we are acclimating into our system and are we going to be taken care of? Below we will briefly discuss the different types of coral and what they require (in general).
It is always important to note that this is an overall and may not be true for every single coral that fits the catalog for one of these three categories. It is always wise to specifically look up the scientific name of any given coral you have brought home from the store and research its specific requirements.
What are the requirements for a soft coral?
Soft corals in general are easier to keep in the aquarium hobby. Soft coral does not have a skeletal structure. These animals are made up of just polyp, stomach and flesh that grow over the surface of an area. These are commonly found growing on live rock. Because they do not have a skeletal structure most soft coral will be fast growing.
The lighting requirements in general for soft coral is low to medium lighting. Although some can tolerate higher and even lower lighting environments. As a basic rule of thumb after you get any coral home, and this goes for soft coral as well, you always want to try placing them in a low light situation rather than a highlight situation. Overtime they can be acclimated from lower shaded areas to moderate lighting. Like most coral, full spectrum is ideal to showcase the color scheme of the animal. Bottom line is that softies will tolerate low to moderate lighting conditions depending on the specific species.
Chemistry being the next component, soft coral are very forgiving when it comes to parameter fluctuations. Again this is not true for every species of soft coral. Generally speaking soft corals can tolerate mild parameter swings for example; slightly elevated nitrates, slightly elevated phosphates and even temperature swings. Human error is something to always consider. Best practice is to check parameters often. It is always ideal to shoot for consistency and stability. As mentioned they may be tolerant to swings but extremes could stress them out and even kill them. Soft coral is not reliant on calcium carbonate for a skeletal structure so monitoring calcium levels will not be crucial. You will however want to ensure that alkalinity and other trace elements are present in the water column as these corals rely on certain compounds and nutrients found in the water. But overall coral like Zoanthids, Mushrooms and GSP will not require much in respect to chemistry.
We will need to touch on flow. Again there is not a “one size fits all” answer to this component. When it comes to soft coral, flow can be the determining factor of slow and fast growth. For example when GSP are in high flow conditions they tend to grow quicker. But on the other hand Zoas will need a more “fine tuned” flow rate. Generally speaking, if you have a powerhead in the tank and you keep softies in the right conditions (meaning not too much and just enough) they will thrive. You will want to see the polyps fully extended with a gentle sway about them. Anything too much can stress the animal to the point where they will close and will not be able to eat. Anything too little and current will not carry nutrients to them.
Lastly, we need to discuss nutrient intake. Corals are animals and although they Photosynthesize, they will need meaty foods as well. Soft corals will rely mostly on photosynthesis but offering them a variety of different meaty powders available on the market is recommended. This does not need to be done very frequently but again there is no one answer for all soft coral.
What are the requirements for large polyp stony coral?
LPS or large polyp stony coral are considered to be mid-level (or moderate) as far as care requirements are concerned. These corals are made up of flesh (stomach and mouth) but also have a calcium carbonate skeleton to their anatomy. Due to relying on a calcium carbonate skeletal structure, these corals tend to grow slightly slower.
The lighting requirements in general for LPS coral is medium lighting. Although some can tolerate higher and even lower lighting environments. As a basic rule of thumb after you get any coral home, and this goes for LPS coral as well, you always want to try placing them in a low light situation rather than a highlight situation. Overtime they can be acclimated from lower shaded areas to moderate lighting. Like most coral, full spectrum is ideal to showcase the color scheme of the animal. Bottom line is that LPS will tolerate moderate lighting conditions depending on the specific species.
Unlike soft coral, LPS will be a little more sensitive to chemistry swings. Although slightly elevated nitrates would be acceptable for LPS it would be recommended to keep the nitrates as low as possible. Phosphates are a different story though. Be it that LPS does have a stony structure it is recommended that phosphates be kept as close to zero as possible. The reason for this is that phosphorus can inhibit the growth of the calcium carbonate structure by tricking the animal into thinking that phosphorus molecules are calcium molecules. This is something that is happening on a molecular level and the easiest way to understand this variable will be to test for PO4 (should be 0.05ppm or lower). Calcium, alkalinity and magnesium will be something else that will need to be tested in the aquarium if LPS are being housed. Calcium and Alkalinity work together (acting somewhat like a see-saw) as magnesium acts like the center point (raising and lowering the see-saw). We will not go into great detail with these elements here but the recommended levels are as follows; Calcium - 400-450ppm, Alkalinity - 8.0-12.0dKH, and Magnesium 1280-1350ppm.
We will need to touch on flow. Again there is not a “one size fits all” answer to this component. When it comes to LPS coral, flow can be the determining factor of slow and fast growth. For example when a torch or a type of Euphyllia is gently swaying in the current, this will be a clear indication of a happy animal and will tend to grow quicker. But on the other hand certain LPS will take a gentle current to ensure their flesh is free of detritus. LPS will need a more “fine tuned” flow rate. Generally speaking, if you have a powerhead in the tank and you keep LPS in the right conditions (meaning not too much and just enough) they will thrive. You will want to see the polyps fully extended with a gentle sway about them. Anything too much can stress the animal to the point where they will close and will not be able to eat. Anything too little and current will not carry nutrients to or from them.
Lastly, we need to discuss nutrient intake. Corals are animals and although they Photosynthesize, they will need meaty foods as well. LPS will rely on photosynthesis but offering them a variety of different meaty powders and meaty frozen/thawed food available on the market is recommended. LPS growth and well being do rely on food offerings. Some examples of Scolymia and Acanthastrea are big food consumers. This should be done frequently but again there is no one answer for all soft coral.
What are the requirements for a small polyp stony coral?
SPS or small polyp stony coral are considered to be some of the more sensitive coral. This of course is not true when it comes to all SPS. When most of us think of an “SPS'' coral we think of Acroporia. Acros tend to be a difficult animal to care for due to almost no room for error. However, other SPS coral can be relatively easier to care for like Montiporia, Seriatopora, Stylophora, and Pocillopora. These corals tend to come in a few varieties of growth patterns; encrusting, branching, and plating. The anatomy of an SPS is similar to that of LPS but will have much smaller polyps. These corals are made up of flesh (stomach and mouth) but also have a calcium carbonate skeleton to their anatomy. Due to relying on a calcium carbonate skeletal structure, these corals tend to grow slightly slower.
The lighting requirements in general for SPS coral is medium to high lighting. Although some can tolerate higher and even lower lighting environments. As a basic rule of thumb after you get any coral home, and this goes for SPS coral as well, you always want to try placing them in a low light situation rather than a highlight situation. Overtime they can be acclimated from medium-light areas to high lighting. Like most coral, full spectrum is ideal to showcase the color scheme of the animal. Bottom line is that SPS will tolerate high lighting conditions depending on the specific species.
SPS will be more sensitive to chemistry swings. Near zero nitrates will be acceptable for SPS - it would be recommended to keep the nitrates as low as possible. Phosphates are a different story though. Be it that SPS does have a stony structure it is recommended that phosphates are also kept as close to zero as possible. The reason for this is that phosphorus can inhibit the growth of the calcium carbonate structure by tricking the animal into thinking that phosphorus molecules are calcium carbonate molecules. This is something that is happening on a molecular level and the easiest way to understand this variable will be to test for PO4 (should be 0.05ppm or lower). Calcium, alkalinity and magnesium will be something else that will need to be tested in the aquarium if LPS are being housed. Calcium and Alkalinity work together (acting somewhat like a see-saw) as magnesium acts like the center point (raising and lowering the see-saw). We will not go into great detail with these elements here but the recommended levels are as follows; Calcium - 400-450ppm, Alkalinity - 8.0-12.0dKH, and Magnesium 1280-1350ppm. As mentioned above, unlike LPS, SPS will need much more consistency when it comes to chemistry. The best way to ensure all levels are consistent is to be consistently testing and monitoring all levels of the aquarium. Certain computer systems are a wise choice when housing these animals as they will essentially do the monitoring for you. Having said that, monitoring is only one part of this - dosing the aquarium to accomplish adequate levels will be crucial.
We will need to touch on flow. Again there is not a “one size fits all” answer to this component. When it comes to SPS coral, flow can be the determining factor of slow and fast growth. For example when an Acro or Monti has its polyps extended, this will be a clear indication of a happy animal and will tend to grow quicker. Another good indicator of “good flow” will be ensuring that the colony is free of any detritus. SPS, generally speaking, will need a higher flow rate. If you have a powerhead in the tank and you keep SPS in the right conditions (meaning moderate to high flow) they will thrive. You will want to see the polyps fully extended. Anything too little and current will not carry nutrients to or from them. Tip: you will notice that high flow is not as concerning as low flow when it comes to SPS - They like the current!
Lastly, nutrient intake. Corals are animals and although they Photosynthesize, they will need meaty foods as well. SPS will rely on photosynthesis but offering them a variety of different meaty powders and meaty frozen/thawed food available on the market is recommended. SPS growth and well being do rely on food offerings. Keep in mind that SPS do have smaller polyps - some frozen foods will be too large. As mentioned, there are a variety of powdered foods acceptable offered in local stores and online. Research your specific animal and select a food that is best suited for them. This should be done frequently but again there is no one answer for all soft coral.
In closing, I will want to mention this is meant to be a quick overview of the three basic categories of coral; Soft Coral, LPS, and SPS. There are ALWAYS exceptions to the rules. Trust me, there are a lot of exceptions. It is always recommended that you research and research again and again before bringing home a new aquarium companion. Remember corals are animals. Each animal is unique in its own way and will have slightly different care requirements. I am confident that we can all have a successful aquarium by researching prior to owning these animals.
