Both beginners and advanced aquarists will experience occasional outbreaks of parasitic diseases like marine white spot (Cryptocaryon, Oodinium). A number of stress factors can be the cause of this problem. For example poor water quality, unsuitable or fluctuating temperature or salinity, as well as social factors.

Especially when a new fish is introduced to the tank the chances of problems occurring are greater. The stress brought about by a new inhabitant, can even lower the resistance of the other fish, so they too may become infected.
Treatment with Copper such as using Red Sea`s ParaCure, is often the only way to save the fish. The Copper ions are quickly absorbed by surfaces and deactivated in the aquarium. For a treatment to be effective the Copper concentration should be maintained exactly at the therapeutic level of 0.3 ppm for at least 10 days.
Lower concentrations will not kill the parasites and may even lead to an increased resistance against the Copper, while overdosing will lead to complications for the fish and even death, since the safety margin of a Copper treatment is very small.
The only way to give a Copper treatment that is both safe and effective, is to test the Copper level daily with a reliable kit and to add more treatment to the recommended dosage as necessary.
Only Copper ions are effective against parasites! By using Red Sea`s Test Lab you are able to accurately maintain the therapeutic level of Copper ions. Chelated Copper has little or no effect.

Copper - As a harmful substance
Although it is a good treatment for fish parasites, Copper is very toxic to invertebrates. ParaCure should therefore never be used in the presence of invertebrates.

Tap water is known to contain Copper in certain areas. This amount could be harmful to your aquarium (especially to a reef aquarium), when you use it for changing water. This Copper Test Lab enables you to check if any Copper is present in your water supply. An amount of 0.1 mg. per liter (0.1 ppm) can already be harmful to marine invertebrates.