Simple and inexpensive.

Certainly it is a hobby that requires dedication and money. Many of us make major disbursements to access the best skimmer or lighting fixture thinking that we will achieve a beautiful reef aquarium, but sometimes we miss some practices and maintenance routines that if applied correctly will produce enormous benefits to our marine system. If you want to have an enviable marine aquarium, these tips are of your interest.

This hobby requires common sense and balance. It is useless to purchase the best equipment if we do not introduce compatible species or neglect maintenance (or we overdo it, which can also be negative).

I'll give you some tips that I think they can be useful for most marine aquariums. Maybe some of them will seem weird and go in the opposite direction to what other authors advise.

Plan maintenance routines

Something that often stays as a statement of good intentions. To have an enviable marine aquarium is critical to follow certain maintenance guidelines established by ourselves. Water changes, glass cleaning, skimmer and other reactors cleaning, pumps cleaning, water tests… It's useless to make some and forget others. An aquarium is a system that requires balance in all its aspects.

Easier to understand with an example:

strawberry shortcake acropora

We may strictly carry out water changes and clean the skimmer and tank walls but if we neglect cleaning the pumps they will eventually move no water and even stop, producing heat, debris accumulation and decreased gas exchange just to mention some of the consequences.

Over time this will lead to a system deterioration.

Stability is key

Marine aquarium inhabitants especially corals are animals with some difficulty adapting to rapid changes on some of its parameters. They have been living in a stable environment for many thousands of years and therefore have not developed mechanisms to adapt to certain changes; they can not regulate their temperature, they cannot wander to keep coming energy from the sun and they can not withstand sudden changes in pH or alkalinity to give an example.

I've seen many hobbyist strive to maintain the nitrate and phosphate level very low, but they do not worry when they suddenly rise because they introduce several fish at once or make a major change in their diet. I've also seen some people keep the alkalinity within the optimal range but every time they do a water change they don't check it and produce a sudden change of a couple of degrees. Every time this kind of thing happens, corals suffer and use to respond by stopping their growth or accumulating zooxanthellae that mask their pretty colors.

Thus, if you want to have an enviable marine aquarium, do not be concerned about the absolute values ​​of the parameters, it is sufficient that they are within range (usually quite broad) and make an effort so that they vary as little as possible.

Choose and plan the introduction of animals

Important, especially on the first months when the aquarium still has not reached a high degree of maturity and stability.

It seems of common sense but we seldom respect this piece of advice, and hobbyist are sometimes too impulsive: we feel captivated by a fish or coral when we see in a store and can not help buying it.

You need to decide what type of aquarium you want and make a list of compatible animals before buying any.


It is also important to establish the order in which we introduce, normally the small and peaceful fish are the first ones to bring in for them to adapt and establish their territory; large or more territorial fish should always enter the last.

Do not rush and enjoy each animal you buy, in this way you will allow them to adapt easily to their new home and let the system remain stable absorbing the increase of nutrients.

If it is not carefully planned, our aquarium can be a battlefield in which the fish do not stop fighting for territory, or disturb the corals and other invertebrates.

Do not let the sediment and debris to accumulate

Out of ten aquariums I see, hopefully one of them has a clean, debris-free sump. These accumulations of stuff, mainly fish feces, usually produce long-term issues and are the cause of high nitrates and phosphates levels.

Keep the sump clean is as simple as placing one or more small pumps (there are very cheap ones, but you want to buy those that are fixed by a magnet holder) or siphoning accumulated matter every time we do a water change.

Use a well dimensioned skimmer

Installing the most powerful skimmer you can buy is a bad advice we have luckily overcome. Oversized skimmers are a big mistake, I cannot say it clearer:

  • They represent a huge financial outlay, difficult to justify.
  • They are bulky equipment, hard to accomodate and extract from the sump to keep them clean.
  • They pull too much stuff out the water, both good and bad, and which is even worse, too quickly. They can turn the aquarium into an almost sterile system.

We should not base the filtration on the skimmer, which will only remove polar substances, i.e. between a 40 and a 50% of contaminants that can build up in an aquarium. On the other hand, an excessively powerful skimmer can be the cause of many corals to close their polyps, especially if we talk about soft corals. It will also remove essential trace elements such as potassium (especially needle-wheel rotors) which inevitably affects the health of many invertebrates.


Aquariums with an oversized skimmer use to lack of micro fauna as copepods, isopods and amphipods, a look on the microscope often reveals a low concentration of bacteria and ciliates, and mono species predominance.

This is a plausible explanation for dinoflagellate outbreaks and other pests that are usual in such cases where an imbalance and any of the nutrients becomes limiting.

Use activated carbon

And a good quality one. A good activated carbon is much more efficient than a skimmer and will adsorb some substances that the latter is not capable to withdraw such as chemicals released by aerosols, smoke substances and many others that are generated as a result of the metabolism of the animals in the tank.

Activated carbon is also very effective removing substances released by some corals to inhibit the growth of other, what is known as “chemical warfare”. It is therefore particularly useful in aquariums with zooanthus, palithoas, discosomas, etc.

Something so inexpensive, so easy to use and so ignored. I have seen aquariums dramatically improve by simply adding a bag of activated carbon. Within a few hours of introducing the activated carbon in the aquarium we can see greater water transparency, be careful with this as you could burn some coral tissue by improving the clarity of water.

There are many types of activated carbon: bituminous, anthracite, vegetal…and two ways to activate them: thermal and chemical (some companies use both). As a general rule it is preferably a thermally activated carbon because the chemically activated ones are usually washed with phosphoric acid and could release some phosphate when introduced into the aquarium. In any case, profusely rinsing is essential no matter the carbon we choose as dust may irritate corals' tissue.

Clean the light fixture diffuser

We sometimes do not realize, but dust and sprayed water can reduce the efficiency of the diffuser in nearly 30%. It is important to clean it regularly, using a damp cloth and taking special care as builtup salt can scratch the acrylic diffuser.

Do not turn your aquarium into a desert

Whatever the type of fish and invertebrates that you keep, if you want to have an enviable marine aquarium do not take organic load to a low extreme.

We must differentiate between nutrients and nutrient flow, two similar but distinct concepts:

  • Nutrients. Are the accumulation of substances derived from the metabolism of animals, such as nitrates and phosphates.
  • Flow of nutrients. It is the balance between incoming and outgoing nutrients.

In a natural reef, the nutrient level is usually very low and the flow of nutrients moderate and constant. Marine currents carry phytoplankton and zooplankton from the cold to the warm waters, it is a small but continuous contribution we cannot imitate in an aquarium without compromising nutrient levels.

A few years ago ultra low nutrient systems were very popular (ULNS), with very pale and faint looking corals. These corals are very delicate, suffer frequent tissue necrosis (STN) and they also grow at a slow rate.

desalwii acropora

Lately, we can admire aquariums showing bright and colorful corals , with marked growth tips and better capability for withstanding any eventuality or imbalance without suffering necrosis in their tissues.

The trend is to increase the feeding amount and variety of foods (and thus the flow of nutrients) and allow a slight increase of nitrates, usually below 0,5 ppm (barely detectable with a NO3 test). To do this nothing better than watching the most delicate corals; and see how the pale colors become strong and vibrant, with depth of color but without sacrificing those rich hues. Growth takes off, which can be noted by performing alkalinity tests in order to adjust the calcium and carbonates to the new situation. Fish and coral are healthier and happier, deceases get considerably lower.

Nowadays we can find enviable marine aquariums with low but detectable level of nitrates.

I hope these simple tips help you focus your marine aquarium maintenance in a more simple and economic perspective.