Having the correct water values guarantees you a functioning and beautiful saltwater aquarium. We’ll show you how to get them.
For tropical marine fish and invertebrates a temperature window between 24 and 27 °C is best. The minimum temperature is 20 °C and the maximum temperature is 30 °C. These temperature extremes should never be allowed to prevail for long. With the help of an adjustable heater (e.g. JBL ProTemp S 25 ) you can choose the best temperature and the adjustable heater will then maintain it automatically. If the water heats up over 30 °C or the water temperature remains at 29 °C for a longer period, then coolers are required ( JBL Cooler ). The JBL premium thermometer indicates the water temperature precisely in 0,5° steps on an easily readable scale. Mediterranean or Atlantic aquariums which don’t get warmer than 24 °C are the exceptions. Here cooling units are required to cool down the water temperature to lower values. But these do not come cheap.
The salt content (or salinity) indicates the content of dissolved salts per kilogramme seawater in parts per thousand (‰). The average salt content of seawater is 34.7 ‰. But it varies depending on the geographic region of the seas. In aquatics a density of 1.022 (normal) to 1.025 (Red Sea) at 25 °C has shown itself to be best, and this corresponds to a salt content of 33 to 36 ‰. The density of the water only plays a crucial role in saltwater aquatics and is measured with a special densimeter, the areometer. With this you have the chance to determine the salinity of the water. Areometers are always calibrated to a specific water temperature. If the water temperature deviates from the calibration temperature you can find the correction factor in the corresponding table. The professional JBL Precision hydrometer has a reading accuracy of 0.0005 units and a built-in thermometer with a temperature correction scale! The areometer value readings are taken at the height of the water surface and not at the height of the water at the glass, which is slightly higher because of the water surface tension! By adding salt or water the density can be adjusted more precisely.
Carbonate hardness (KH) is one of the most important factors for a functioning saltwater aquarium. The KH stabilises the pH value of the water and is thus the life insurance of the aquarium. The carbonate hardness should never drop under 7 or rise above 10 °dKH. While higher values are not harmful they often cause problems with other water parameters. Thus KH levels over 10 can complicate matters when you adjust the calcium and magnesium values to the level you require. Increase: By adding JBL CalciuMarin you increase the KH and the calcium content. A chalk reactor provides a technical solution to increase the KH and the calcium level. Here calcareous material is flushed with water in a separate container. By adding CO2 (carbon dioxide) the pH value in the chalk reactor decreases to about 6 and the chalk dissolves in the water, which then gets added into the aquarium drop by drop. With the JBL KH Test you can exactly determine the KH value of your saltwater in a few minutes.
The pH value indicates the acidity of the water. Saltwater is alkaline and shows pH values between 7.9 and 8.4. A pH level of 8.0 is ideal in the morning and it may rise during the day to 8.3. In case your pH value is too low or even too high, please check the KH which stabilises the pH level. If the carbonate hardness is too low it mostly comes to strong fluctuations in the pH value. As soon as the KH is back in the correct range between 7 and 10 °dKH again, the pH level should also be back in the correct range. If you run a biological filter (consisting therefore not only of mechanical filter material), this filter will produce acids to make your pH value drop. Add a little coral gravel into the filter as the last filter material. This will bind the acids which have formed and will additionally dissolve a little of the beneficial KH and calcium into your water. An incorrectly set chalk reactor is another common cause of low pH values. The water INSIDE the chalk reactor needs to have a low pH value of about 6.0 and be added to the aquarium drop by drop. If too much water is added to the aquarium, even with this low pH value, it will also lower the pH level.
Calcium (Ca) is a very important macro element which corals especially, but also other invertebrates and fish, require for healthy growth. The calcium content of seawater lies between 380 and 460 mg/l. Ideal are values at 440 mg/l. Far higher values don’t improve the coral growth and cause problems with other water parameters, such as KH and magnesium. By adding JBL CalciuMarin you can increase your calcium level. A chalk reactor provides a technical solution to increase the KH and the calcium level. Here calcareous material is flushed with water in a separate container. By adding CO2 (carbon dioxide) the pH value in the chalk reactor decreases to about 6 and the chalk dissolves in the water, which then gets added into the aquarium drop by drop. With the JBL Magnesium/Calcium Test you can exactly determine the KH value of your saltwater in a few minutes.
Magnesium (Mg) is, together with the carbonate hardness and the calcium content, the third factor which needs to be measured regularly and corrected if necessary. In the oceans the magnesium levels are between 900 and 1400 mg/l. In aquariums a magnesium level of about 1200 mg/l has proven to be best. With too low magnesium contents the desired coralline algae don’t grow at all or only weakly. Too high magnesium contents are also not useful because water with too high magnesium levels has only a limited absorption capacity for minerals and salts. When this absorption capacity is exhausted, other important minerals can’t be dissolved in sufficient quantities or they precipitate. By adding JBL MagnesiuMarin you can increase your magnesium content to the ideal level.
Ammonium (NH4) constitutes the first stage of the nitrogen degradation .There shouldn’t be any ammonium measurable in aquariums which have been in operation for more than 4 weeks. Higher ammonium values only occur at the first stage in a new aquarium. At pH levels over 7.0, part of the non-poisonous ammonium transforms into toxic ammonia (NH3). That’s why it’s important to carry out a pH test as well as an ammonium test to find out, by using the tables provided, how much ammonium has been transformed into toxic ammonia. Higher ammonium levels imply a bacterial imbalance which could have been caused by adding medications, as an example. By adding JBL Denitrol you add millions of living and ammonium-degrading bacteria into your saltwater.
Nitrite (NO2) is created during the bacterial degradation of ammonia and is highly toxic for fish. In a healthy aquarium the nitrite instantly converts into nitrate (NO3) and is therefore not measurable anymore. A measurable nitrite value indicates a problem with the bacterial balance of the aquarium, and the cause for this needs to be investigated. As an example, an additional medication can have a negative influence on the bacterial balance. By adding JBL Denitrol you add millions of living and ammonium- and nitrite-degrading bacteria into your saltwater.
Nitrate (NO3) is non-toxic but it is an algae nutrient. Low nitrate concentrations in the saltwater aquarium strengthen the growth of many corals. With nitrate concentrations over 50 mg/l we recommend the use of a special filter material ( JBL BioNitrat EX ), where bacteria settle and break down the nitrate due to the low oxygen content inside the material. If you have a lot of corals and the nitrate values tend to approach zero, you can stimulate the coral growth by adding nitrate. A product from the freshwater aquatics JBL ProScape N Macroelements ) is suitable for this. The dosing needs to be tested in small steps.
Phosphates (PO4) are harmless for fish and invertebrates but, as main nutrients for algae, they are the basis for algae growth. If you have problems with excessive algae growth, measure the phosphate value of your water (also the starting water, where you later add the salt). Simply reduce too high phosphate levels by adding an efficient phosphate remover ( JBL PhosEX ultra ), which removes phosphate from the water without side effects.
With the JBL Water Analysis Online Laboratory we give you the opportunity to enter your water values directly and have them analysed by us.