Reef aquarium

The most important chemical water parameters to measure regularly at home in reef aquaria are alkalinity, as well as concentrations of calcium, magnesium, phosphate and nitrate. You can find our recommendations for the respective tests in the section Water analyses for reef aquaria.
For the concentration determination of all other macro and trace elements we recommend an ICP based element analysis. You will also find a recommended selection of products for this in our Seawater Solutions Shop.

Our Customized Reef Supply is a complete supply system for reef aquaria. For optimal functioning of the system, it is only necessary to measure the concentration of calcium and magnesium, as well as alkalinity at regular intervals at home. When starting a reef aquarium, as well as after changing supply systems, it is necessary to initially test these water values every 2-3 days and then adjust the dosage amounts. All our products contain dosing instructions, which make it easy to set the daily dosing amounts.

In marine aquaristics, elemental analyses are often referred to as ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy) for reasons of simplicity, since this method can be used to measure most of the elements in our water samples. This method is therefore only able to detect the concentration of individual elements in the investigated water sample. However, behind the results of these analyses lie often several measurement methods, such as ion chromatography, since some elements are difficult to analyze in ICP-OES. In addition, the analyses of some suppliers also indicate the concentrations of various compounds. This includes, for example, phosphate (PO4), which can be calculated on the basis of the measured phosphorus concentration (P). Other compounds such as nitrate (NO3) or alkalinity (amount of CO32-) have to be measured in the laboratories by photometry or titration. Summary: A single ICP-OES can only give information about the concentration of elements (e.g. Ca, I, Sr,...) and not all elements can be measured in the ICP-OES. Also compounds of several elements often need further analytical methods. In our store you will find a selection of water analysis for marine aquaristics recommended by us, which take into account all these aspects and therefore offer the widest possible range of results.

The largest proportion of nitrate in the aquarium is produced by the fish that we put in the aquarium. These excrete ammonia as a metabolic breakdown product through their gills (90%) and urine (10%), which is then usually converted to ammonium (this process depends on the pH value!). Through the so-called nitrification, a bacterial metabolic process, ammonium is first converted to nitrite and then, in a further conversion, to nitrate, which we then measure with our water analyses. The nitrate value is also influenced by the metabolism of other animals such as snails, crayfish, echinoderms,... .

In the early days of marine aquaristics, one was often faced with the challenge of reducing the amount of the important nutrients nitrate (NO3) and phosphate (PO4). With today's state of the art technology, such as the establishment of highly efficient protein skimmers and various filter media and adsorbers, it is relatively easy to adjust the nutrients in moderate concentrations. 

1. Tip:
An excessively high nitrate level is usually the result of too many fish in the aquarium. A consultation with your trusted retailer should therefore take place before buying fish, if possible, to avoid overstocking the tank. This can be counteracted by wetting the skimmer. Therefore, the height of the water column in the reaction body of the skimmer is increased, resulting in stronger skimming. 

2. Tip:
Another simple step is the introduction of additional consumers into the aquarium. In the classic reef aquaria these are mainly corals, which use the nitrogen compounds from the nitrification chain for their photosynthesis and can thus produce energy, which allows them to grow. You can also find out which corals fit into your aquarium from your retailer. 

3. Tip:
In addition, increased nitrate content can be counteracted by adding carbon supplements. For the dosage of carbon you will find an extra entry.

Due to the now very efficient technology, nutrient limitations occur in many aquaria. Especially when stocking with fish is not possible due to a too small size of the tank. This means, that the corals, algae, etc. consume more nutrients than supplied by the other living organisms through their metabolic end products. 

This problem can be managed very well in large aquariums by a higher fish stocking and the increased feeding that goes along with it. 

In addition, you can set the skimmer drier, so that less skimming is performed and therefore more nitrogenous protein compounds are available in the water. 

If all these steps do not work and the animals continue to show signs of nutrient limitation, you can increase the nitrate content by dosing suitable supplements.

We speak of nutrient limitation as soon as proven by too low nutrient concentrations, negative symptoms are visible in the animals in our aquaria. These symptoms can manifest themselves in corals, for example, as stagnant growth or even tissue loss. 

A definite value, from when it actually becomes a limitation, varies from tank to tank and can therefore not be defined exactly. A perfect cycle in the aquarium would be given if all living organisms through their metabolism release exactly the amount of nutrients into the water, which are then in turn used up by autotrophic organisms (i.e. mainly corals, algae, etc.). So in this situation, both the nitrate and phosphate concentrations in the aquarium water could not be detected with our native tests, but the corals would have exactly the right amount of nutrients available. In practice, however, it is extremely difficult and a dance on a knife edge to induce exactly this situation. In addition, in many cases, even with low but clearly detectable nutrient concentrations in many tanks, classic symptoms of nutrient limitation occur, which can also be stopped relatively quickly by specifically raising these deficits. 

So every reef aquarist should find out the right nutrient concentration for his own individual reefaquarium. Values at which we have never been able to determine negative effects on our animals are nitrate: 5-10 mg/l and phosphate 0.03 - 0.08 mg/l.

Unlike freshwater aquaria, reef aquaria can hardly do without cleaning the glass. In addition, the skimmer pot must be emptied at regular intervals and the technology such as water and flow pumps must be cleaned and decalcified to ensure a long service life with optimal functionality. How often these intervals for cleaning the aquarium glass and technology accrue differs from tank to tank and depends, among other things, on the nutrient concentration and the associated algae growth.

Nearly all animals in a classic reef aquarium originally come from the tropical zones of our earth and are adapted to a daily rhythm of 12 hours. Thus, in our opinion, the optimal lighting duration is also 12 hours per day in the reef aquarium. In addition, a slow dimming of the lighting in the morning and evening is recommended - if technically possible - to slowly accustom the animals to the bright light and to simulate a more natural course of the day.

Unlike in freshwater, only small partial water changes are required in marine aquaristics. Due to the usually high density of corals in the aquarium, there is normally no accumulation of metabolic waste products and nutrients. A weekly water change of about 10% is nevertheless advisable to achieve more stability in the aquarium. 

This question is as important as it is difficult to answer. The cost of the aquarium is extremely dependent on the technology used and the desired animals. So you should think beforehand how the aquarium will ultimately be occupied.

It is also always important to consider the running costs. Especially the power consumption is an important factor in the planning of the aquarium. For example, if it is to be a pure soft coral and fish aquarium, a somewhat more economical and cheaper lamp is usually enough. In addition, the costs for soft corals are usually lower than for rare stony corals. 

With the acquisition costs for the technology, you can save money relatively easy by buying used products from private. Here, however, it should be ensured in any case that the articles have no age-related impairments and are still up to date. Due to the aggressive properties of salt water necessarily also pay attention to the flexibility of the cables and any cable breaks! 

You should always keep in mind, however, that saltwater aquaristics is certainly not the cheapest hobby. It is helpful to make a rough cost breakdown with the desired technology and the stocking of the aquarium. 

In the specific case, we are happy to assist in the planning of the aquarium.


This question is difficult to answer. Here, factors such as aquarium size and setup, previous stocking,... a decisive role. A conversation with the pet shop of your confidence should help here.

We have created a step by step guide in English for you. You can find it here: HC Hanna Instruments Checker manual


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