The pH value in a marine tank has a major impact on the growth of corals and calcareous algae and on many biological processes.

The pH should not be allowed to fluctuate more than approx. 0.2 units during any 24 hour period and should preferably be kept above 8.2.

If the pH is too low then the cause may be a too low alkalinity and/or a build up of carbon dioxide caused by insufficient aeration

A low pH can be corrected by improving aeration and by increasing the alkalinity using the Salifert KH + pH buffer additive.

The Salifert Test Kit is sufficiently accurate to monitor minor pH fluctuations and is scaled from pH 7.4 - 8.7.

Sufficient for 50 tests.

Carbonate hardness/Alkalinity Profi-Test

• Calcium is not the only substance needed to form the skeletal material of corals and allow calcareous algae to grow. Carbonate and bicarbonate are also needed and these two substances can have a major effect on stabilizing or buffering pH levels in the aquarium in the correct range of 8.1 to 8.4.


• The total carbonate and bicarbonate concentration is also called alkalinity or carbonate hardness and for a stable system the alkalinity should not fluctuate by more than 5% from the optimum level of approx. 2.8 meq/L i.e. a maximum fluctuation of 0.14 meq/L.


• The Salifert test is sensitive enough to detect small changes in levels of alkalinity, measuring in steps of 0.1 meq/L and demonstrating a very sharp colour change.


• Sufficient for 100 to 200 tests.


• The Salifert KH + pH buffer additive makes correction of the alkalinity or carbonate hardness simple and does not upset the pH of the system

When there are insufficient areas of a tank which are deprived of oxygen (anaerobic zones) or denitrification is not taking place properly, nitrate will build up. This can also happen in an aquarium where the biological loading on the system is causing an imbalance e.g. is there is excessive livestock for the aquarium volume or over feeding is occurring.

The build up of nitrate can result in unwanted algae growth and the slowing down of coral growth.

The nitrate concentration in a reef aquarium should be lower than 1 mg/L, although fish only aquariums would usually have a higher concentration.

Just as with nitrite, many nitrate test kits are prone to amine interference which can make the levels of nitrate appear much lower than they actually are.

The Salifert test kit does not suffer from such interference and gives accurate and quick results with a total testing time of less than 3 minutes.

This test offers two ranges :

Low Range : 0.2 - 10 mg/L (ppm)

High Range : 2 - 100 mg/L (ppm)

If phosphate is present in too high a concentration there may be an increase in growth of undesirable algae and if the phosphate level is higher than 0.04 mg/L the growth rate of corals and calcareous algae may decrease by as much as 90%.

Washing fish food (a rich source of phosphates) after thawing can significantly reduce the input of phosphate, and using a high grade, phosphate free activated carbon can also help to keep phosphate levels as low as possible.

The Salifert Phosphate test kit detects, in less than 5 seconds, the level of phosphate present.

There are two different ranges within the kit: a low range for phosphate-phosphor from 0.01 - 1 mg/L and a medium range for phosphate-phosphor from 0.02 - 2 mg/L.

Sufficient for 60 tests.

Corals and marine fish require very high levels of oxygen concentration because of the low solubility of oxygen in salt water so it is very important to regularly test the level of oxygen present.

The Salifert Oxygen Profi-Test is extremely fast, measuring oxygen levels in just a few minutes and is scaled from 2 - 14 mg/L.

Ammonia and ammonium should be rapidly converted by aerobic nitrification into nitrite and then nitrate and finally into nitrogen gas. If this does not happen then either the aquarium is not fully matured or there is a problem with the tank's biological system, which can be caused by an excessive biological loading being placed on the system.

The Salifert Test Kit measures the total amount of ammonia and ammonium quickly and accurately.

Calcium is a major constituent of coralline algae, the skeletal material of hard corals and the skeletal needles of soft/leather corals. In many cases too low a calcium concentration retards coral and coralline algae growth. Calcium also fulfils many important biological functions.

In a healthy aquarium, the growth and multiplication of corals, calcareous algae and other organisms can result in calcium depletion.
To maintain a stable environment it is important that the calcium content should not fluctuate by more than 15 mg/L from the optimum range of 420 - 450 mg/L so regular testing should be carried out.
This means that any calcium test used should have an accuracy of significantly less than 15mg/L otherwise it will be difficult to monitor such fluctuations.

The Salifert test kit measures in steps of 5 mg/L and has an accuracy of 10 mg/L.

The colour change is precise, detecting small but significant fluctuations in the concentration of calcium.

The test is not affected by magnesium.