If you have an established saltwater aquarium that is ready for keeping corals, you may be wondering what types of corals are best for a mixed reef tank.
Mixed reef tanks are one of the most desired setups to keep in the saltwater aquarium hobby.
With so many coral options available and thousands of different combinations, it can be difficult to decide which corals are best to be mixed together.
Of course, some absolutely can not be placed in the same tank and others need a certain amount of space in between to avoid being stung.
If you are planning to have a mixed reef tank, it’s important to plan for the long term and do your research ahead of time.
In this article, I will show you some of the best coral choices for a mixed reef tank.
What is a mixed reef tank?
Mixed Reef Tanks contain various groups and types of corals which include SPS, LPS, and soft corals. These tanks are not limited to just one coral type. You can also have reef safe fish and invertebrates including shrimp, crabs, and anemones in the same tank.
Problems with keeping a mixed reef tank
As amazing as mixed reef tanks are, I recommend not keeping one if you are a beginner. Any tank that you want to keep SPS corals in needs to be mature and healthy with all parameters in check. Even if you are not planning to keep SPS you still need to make sure the system itself is ready for corals.
Lighting requirements
Lighting can be a huge problem for mixed reef tanks. The lighting demands for certain corals are different than others. For example, you may have a mixed reef tank with soft corals like mushrooms, leathers, combined with a few LPS corals like Acans, and zoanthids. These corals don’t have a requirement for high lighting and adding them into a tank that needs high lighting for certain SPS corals can lead to serious problems.
SPS corals like Pocillopora or Montipora which do have a requirement for higher lighting would be a bad choice for low lighting tanks. It can be a huge undertaking to find proper areas of the tank for the corals to receive the right amount of light. You can run into a situation where the coral’s health is suffering either because of too much light or not enough.
Water movement
Proper water flow is crucial for the health of all corals. This can be difficult for a mixed reef tank where certain coral types prefer low flow and others need high flow.
SPS corals like Acropora need higher water flow with a varied flow pattern. Soft and LPS corals prefer a low to medium with a gentle flow pattern.
Water Parameters
Although we should aim to have the best water quality possible for our corals, there are some corals that can do better than others in water that is not pristine.
Many SPS corals can be very sensitive to water parameter swings and changes. Stability is key for healthy SPS. There are certain corals that can handle small swings in temperature, nitrate, phosphate, and other parameters while others can’t. You may get away with a less than stellar maintenance schedule with certain corals in the soft and LPS category that are not in a mixed reef tank. But once together in a mixed reef with SPS, your maintenance routines will need to be on par.
Coral stinging
Another concern with a mixed reef tank is that certain corals have the ability to sting others which can damage or even kill them. It’s important to know which corals can be next to each other and which ones can’t. You will need to leave the appropriate amount of space in the tank to prevent this. With a mixed reef tank, this can be more difficult where there are various coral types to prevent stinging others.
Coral feeding
Not all corals require feedings but many of them will benefit from it. If you have a dedicated tank of specific corals that you either don’t feed or only feed sparingly, this could change once you place them into a mixed reef tank. You will end up feeding more often if place together with corals that require frequent feedings. Not only is this an extra step that you might not do in a dedicated coral tank, but it will be an extra cost as well.
Overstocking
With a mixed reef tank, it is very easy to overstock the tank. At some point, you will want a few corals of each type and quickly run out of real estate in the tank.
Fish/inverts
There are certain fish and invertebrates that should not be kept in a reef environment. There are also certain fish and inverts that may be suitable to keep with some corals but not with others. This can be a challenge if you are wanting to keep a mixed reef tank with specific fish. For example, you may have a fish that only picks at soft coral types but not others. So as long as you have no soft corals in your tank you would be fine. But if you have a mixed reef tank where there are soft corals, you couldn’t keep that same fish in the tank. The same with invertebrates.
Best corals for a mixed reef tank
If you can meet the above-mentioned demands for the coral types you plan to keep, there are many options available to you.
For the most part, any coral that is a member of the same genus can be together in the same tank.
If you want to mix soft corals with LPS and SPS in the same tank, here are some great choices. There are endless possibilities so I can’t cover them all but I picked a few ideal corals that work well with mixed reefs environment.
Mushroom corals, Zoanthids, Frogspawn, Acans, Montipora, Birdsnest corals are a solid mix of soft, LPS, and SPS that will do well together. Providing you give them plenty of space.
The Montipora and Birdsnest are not as demanding with high light as other SPS corals and can handle the low to medium lighting for the other corals in the group.
If you are looking to add LPS corals that can handle higher lighting, consider Chalice and Favia corals. They can also handle the higher water flow demand of SPS corals.
Most soft corals like leathers and mushrooms can be in the same tank with LPS corals. Always ensure there is enough space for them to grow and not sting each other. Torch corals can give a nasty sting so leave around 6″-10″ or more space in between them and others.
I would avoid any tough to keep corals in a mixed reef environment. For example, Acropora is a very demanding SPS coral that requires near-pristine conditions in order to thrive.
Which corals can touch each other?
As your mixed reef tank matures and the corals grow, It can be difficult to prevent them from touching each other. This is only a concern if you have corals that will sting. Unless you remove or frag the corals, it is inevitable that your corals will touch.
The following corals can be together in a mixed reef tank and can touch without issues.
- Frogspawn and Hammer corals
- Zoanthids
- Mushroom corals
- Acropora (They can be very aggressive but sometimes are ok with other Acros)
- Leathers
One thing to remember is that corals are animals and not plants. They all have certain personalities and it can be hit or miss if they will get along. Sometimes it works and other times it doesn’t.
Most SPS corals can not touch each other. There are a few exceptions but it’s best to leave space in between them to avoid one from killing the other. They can be very aggressive so it’s crucial to do your homework ahead of time.
Mixed reef tank water parameters
For all coral tanks, you want to ensure that the water parameters are within certain limits that will keep your corals healthy. Mixed reef tanks follow the same parameters as dedicated coral tanks and it’s even more important to follow as some corals will be more sensitive than others.
Here is a chart of the normal water parameters to maintain.
Summary
Anyone who has been in the hobby for a while may want to keep a mixed reef tank. These are some of the most stunning tanks to see. The most important part of keeping a mixed reef is to plan for the long term. This means having a routine maintenance schedule, plan all your equipment accordingly for the different coral types, only keep corals that are compatible, don’t keep fish or invertebrates that are not considered reef safe. There and many other things to consider but this guide will help you get started with a new mixed reef tank the right way.