Aquarium Types Depending on the Coral Population

Depending on the corals we keep in the aquarium, we can distinguish three types of marine aquariums. In addition to these, there are also saltwater tanks populated only with fish (fish only) or so-called fish only with live rock (FOWLR – only fish with live rock). In this article, we will look at the division of aquariums according to corals populations.

Soft corals + LPS

The first type is an aquarium that is populated with soft corals, such as Clavularia, Sarcophyton or Sinularia, and LPS (large polyp stony) corals, such as Caulastrea, Euphylia, Goniopora. 

The possibility of combining the above animals in one tank is due to the fact that maintaining them is relatively easy for a beginner aquarist. Soft corals do not build calcareous skeletons while LPS corals build them, but they are relatively simpler to maintain than SPS corals. 

Soft corals grow quickly, do not need intense water movement or large amounts of light, and are quite resistant to aquarium changes. LPS are also quite simple to maintain although, due to their great diversity, we will also come across very demanding ones. 

Keeping soft and LPS corals is recommended at the beginning of the marine aquarium adventure, as they are quite forgiving of the aquarist’s mistakes (especially the soft ones). It is important to approach the initial purchase of corals with reason and choose the simplest ones, as we are dealing with live animals. The size of the tank is arbitrary and so you can also build a small aquarium that does not take up much space. Just be sure to follow the rules.

In the tank sometimes also present, for example, clams and fish. It is necessary to remember about constant supplementation of micro and macronutrients, as corals constantly consume them. Some LPS need to be fed e.g. krill while others are active at night and will require food dosing after dark. Some species can become fish food and so this should also be taken into account when building the population. It is worth mentioning the beautiful colours of soft corals and LPS, with which they attract our attention, and it is often for this reason that we decide to run a marine tank with a population of soft corals and LPS.

SPS corals (SPS dominated)

Another possibility is an aquarium with 100% planting of hard corals or SPS (small polyp stony) corals, e.g. Acropora, Montipora, which build very skeletal and have a small polyp. As a rule, they are more difficult to maintain, do not forgive mistakes, require very stable water conditions, strong lighting and water movement, and do not grow as fast as soft corals or LPS. 

They are characterised by beautiful colours and, as in the case of LPS, we will also find among them easier and more difficult species in terms of the requirements of water parameters. More difficult will be Acropora, and easier Montipora, Seriatopora or Stylopora. It is less common to find small tanks and more often the large ones, which are easier to manage and more stable. Usually it is these tanks that are equipped with the best technology for its operation to increase the efficiency of aquarium keeping or the safety of animals like skimmer, dosing pumps, calcium reactor or smart devices. Systematic supplementation of micro and macronutrients is required. However, even here there is a wide range in terms of the conditions required by corals and some of them very easily, grow almost like weeds.

Mixed reef aquarium (Mixed reef)

Mixed style is the most common option. In one tank, we breed both soft corals, LPSs and SPSs. This allows you to diversify life, enjoy the beauty of each type of coral, build a cross-sectional tank. It is necessary to skillfully select the cast, because not all corals coexist well with each other. As a rule, corals of different types should not touch each other. It should be taken into account that some cannot be bred with others at all, as they wage chemical wars among themselves. In addition, we can populate our aquarium with clams or anemones. We can also find shrimps, snails and crabs.  Mixed aquariums can be very beautiful!

Other types of aquariums 

Aquariums planted with NPS (non-photo) corals, e.g. Scleractinia, Alcyonacea.  These are animals that do not have zooxanthellae, or algae that coexist with the coral. Due to this attribute, corals cannot use the products of photosynthesis of zooxanthellae (i.e. food from this source). 

Maintaining such an aquarium is demanding, as the animals must be fed while they do not require lighting. These are unique animals, rarely found in domestic tanks characterised by very strange shapes. The main challenge in keeping these corals is that they require very clean water and at the same time they need to be fed systematically and in large quantities (even several times a day, and as we know every food pollutes the water to some extent. Automatic feeders are increasingly used. It is necessary to take great care of the quality of the water so a skimmer will be a minimum, and in addition UV sterilisers or even refugiums are used.

A tank with soft corals alone is also a popular solution. The method of keeping it differs from the others, because, as we already know, they do not build calcareous skeletons hence the supplementation of micro and macro elements will be different from aquariums where we have corals consuming, for example, KH, Ca, Mg or other elements in large quantities. In the case of these “tanks”, the main attention should be paid to NO3 and PO4 levels, elevated levels of which may simply be the result of feeding fish. Aquariums with soft corals can be very beautiful, and an example is Zoa garden.