Instructions for setting up a saltwater aquarium

Here you will learn how to set up your saltwater aquarium properly, so that it continues to look attractive and work longer.

By following a few instructions during the setting up you will prevent any problems from occurring right from the start. Saltwater aquariums require slightly different technology and a little more attention than freshwater aquariums. But it’s no problem to start off with a saltwater aquarium, without having had a freshwater aquarium first. There are nano saltwater aquariums, but we still recommend at least 200 litres for the start because this water quantity is more forgiving.


Install the aquarium cabinet in a suitable place. A suitable place gets little or no direct sunlight. If an aquarium with more than 300 litres is to be installed you need to check the bearing capacity of the floor.


Cut a suitable aquarium underlay (e.g. JBL AquaPad ) to the required aquarium size and place it properly on the cabinet. The underlay will prevent the bottom glass from cracking.


Position the aquarium on the underlay and clean it. Do not use any chemical detergents. Take a clean sponge (e.g. JBL Spongi ) when using water and JBL Clean A for the cleaning.


Before inserting living reef rock into the aquarium, water needs to be filled in and sea salt added. ALWAYS fill the tap water or osmosis water FIRST and then add the salt - never the other way round!


Dissolve as much sea salt in the water until the hydrometer ( JBL Areómetro ) indicates approx. 1.025 at 25 °C. You can use tap water if it is free of nitrate,phosphate, chlorine and silicic acid. You can check this with the corresponding water test.


If not, the tap water needs to flow through a reverse osmosis system which removes most of the pollutants. Additionally you can subsequently use nitrate, phosphate and silicate removers, to get those algae-promoting substances out of the water.


The Aquecedor com termostato (e.g. JBL ProTemp S25) heats the water to the desired 24 – 26 °C. Do not allow the water temperature to deviate from this range for long. As minimum only 20 °C and as maximum only 29 °C are possible.


Subrate: The opinions differ here. Some believe substrate is superfluous and they point out that sludge can deposit in the substrate. Others believe it is good to use substrate because it allows additional beneficial bacteria to settle and provides a place for many animals to search for food or hide. We recommend adding a thin layer (about 2-4cm) of coral sand/coral gravel (medium grain size).


Connecting the filter: If your aquarium is equipped with an overflow system, the water will be directed down through an overflow shaft into a filter basin. In this filter basin a biological and mechanical filtering of the water takes place before it reaches the protein skimmer. We recommend you install a fine filtering BEFORE the biological filtering. This only entails placing a layer of filter floss ( JBL Symec VL ) over the biological filter material and replace it regularly (when it looks dirty). An additional tip: Biological filters produce acids which make the pH level in the saltwater drop. It is therefore helpful to let the water flow through a sack (e.g. JBL FilterBag fine ), which is filled with coral gravel, after the biological filtering.

CristalProfi e 1901

If you have an aquarium without an overflow system, we recommend you use a filter which is as big as possible, such as the JBL CristalProfi e1901 greenline * . It is important to inoculate the filter with filter bacteria ( JBL Denitrol ).


Protein skimmer: This technical device will help you to remove any proteins from the water before they get broken down to nitrate by (algae-promoting) bacteria.


For aquariums without an overflow system you can use protein skimmers which are attached inside the aquarium (internal skimmers).


Let the aquarium run with only substrate, saltwater, heater and filter and WITHOUT lighting for at least one week. Then, after 1 week switch on the lighting one hour longer every week until a maximum duration of 10 hours lighting has been reached per day.

After one week you can gradually start to insert living reef rock (still without light!). There are several ways to design the structures in the saltwater aquarium. Firstly you can build a base made of porous stones to place on that “live rock”. Or you can invest a little more money to build the entire “reef” with “living reef rock”. We recommend the second method because live rock supports the biology inside the aquarium more than “dead” porous rock.


The total running in time therefore amounts to about 12 weeks! But even during this time you will be able to experience quite a lot of beautiful and interesting creatures in your saltwater aquarium which will have entered your aquarium with the living reef rocks.


To prevent sludge deposits (organic debris, sediments etc.) under the rocks, which can lead to algae problems, we recommend the positioning (depending on the aquarium size) of 1 – 3 small pumps ( JBL ProFlow t500 ), which - when required - can be briefly switched on, to “blow” the sludge deposits out from underneath the reef stones, and into the filter.


Lighting: Always make sure that D lamps and no NDL lamps are inserted in metal-halide lamps. For fluorescent tubes preferably use T5 tubes (the slim ones with only 16 mm in diameter) instead of T8 tubes with a diameter of 26 mm, because the T5 tubes have a higher light output. A saltwater aquarium should at least be equipped with 2 tubes. For 2 tubes we recommend 2 x JBL SOLAR MARIN DAY . You need at least 3 tubes before a blue one ( JBL SOLAR OCEAN BLUE T5 ULTRA 24-39 W ) can be added. For 2 tubes we do not recommend a blue light because one daylight tube alone is not sufficient for light hungry corals. Good high-performance reflectors, such as the SOLAR Reflect T5/T8 double the light output and are strongly recommended. If you prefer LED lighting, think about waiting a year before making the investment. LED technology is advancing with great strides. But it is not yet quite where we would like it to be.


It is completely normal in the first 3 months for your aquarium to pass through phases, where it does not always look nice. Sometimes brown algae appear at the beginning and this covers the bottom and the decoration with a very fine brown film.

Faedige Algen

Green filamentous algae can appear, but this should disappear again after some time.

hoehere Algen

When the water is stable, more beautiful “higher” algae and perhaps even invertebrates will begin to grow. But don’t give in to the temptation to add fish. The aquarium is not yet in a position to tolerate the water pollution caused by feeding and fish excrements.

Valores da água

Checking the water values: In the saltwater aquarium some water parameters need to be checked weekly with easy to use water tests and – if necessary – to be adjusted. In our Análise da água, laboratório online you will find hints for the correction of water values, if required.

Proscape N Duenger
  • Carbonate hardness (KH): should be between 7 and 10 °dKH
  • pH Value: should be between 7.9 and 8.5
  • Calcium: should have a value from 400 to 460 mg/l
  • Magnesium: should be between 1200 and 1400 mg/l
  • Nitrogen compounds (ammonium, nitrite and nitrate) should not be detectable.
  • For a lot of corals and a few fish the adding of nitrogen (JBL ProScape N fertiliser) can be useful.

If, after 3 months, everything remains stable and there are no signs of an increased growth in unwanted algae, invertebrates and fish can gradually be added.


Trace elements: Corals, sponges and other invertebrates consume trace elements which are, together with the sea salt, dissolved in the water. With its TraceMarin range JBL has a scientifically proven method of re-dosing trace elements. By the way: Protein skimmers remove a high percentage of the vitamins and trace elements! It’s vital to re-dose more often if a strong protein skimmer is in operation.


Feeding: We recommend that you only add corals which not need to be fed separately because excessive water pollution might occur as a result of this feeding. Fish need to be fed daily but only as much as the animals can eat within a few minutes. JBL offers with JBL Maris , JBL MariPearls , PlanktonPur , JBL Spirulina and JBL Krill a balanced food range which can be supplemented with live food and frozen food. It is useful to add a few drops of vitamins twice a week ( JBL Atvitol ), to strengthen the fish’s resistance to disease.

Finally the most important point: Be patient during the running in phase and withstand the temptation to add fish and invertebrates too early! It’s worth it!!