Warning!  The product dosages provided in the following instructions are what are effective in killing parasites, but do not consider their adverse effect on the fishes.  New scientific studies have shown that Copper treatments on fishes are not recommended except in very special cases, because of possible toxicity to fishes of copper ions in the water at 5 parts or more per billion.  At these levels the copper ions may destroy the fishes' sensory organs and impair the fishes' physiology.  See under BEGINNING AND ADVANCING AQUARISTS AND POND KEEPERS the article The Importance of Removing Heavy Metals From Aquarium and Pond Water.  Under FISH HEALTH see the article Copper Ion vs Chelated Copper Treatments in Aquariums and Ponds. 

For treating fishes, the Kordon products recommended are the Chemical Treatments other than copper treatments, and all the Organic Herbal Preventatives and Treatments. Of all of these the safest to use are the Organic Herbal Treatments -- Ich Attack, Prevent Ich, and Rid Fungus.

GENERAL DIAGNOSIS OF PARASITIC DISEASES OF FISHES
The following brief summary of clinical signs often associated with the parasitic protozoans discussed above is intended only as an aid for the beginning aquarist. It is not to be thought of as a definitive diagnostic key. It is also important that the aquarist consult appropriate, accurate references for more specific information regarding disease problems of marine fishes. In addition, if possible, skin and/or gill smears should be made and examined by a qualified fish diagnostician. Microscopic examination is recommended and is always essential for confirmation of a particular disease. In the clinical signs indicated below, a particular description may be followed by a specific disease causing organism in brackets. This indicates that there is a high probability that the cause of the disease you observed on the fish is the organism indicated in the brackets. It should be qualified that different clinical signs can be seen during the disease process and that these can occur as the result of more than one disease causing organism.

Clinical Signs:
Increased respiration; hemorrhagic body lesions; loss of normal body coloration; scratching on objects or tank bottom; white opaque to grayish papules on skin, gills and eyes of the host [Cryptocaryon]; randomly distributed powdery or dust-like spots on body, having a yellowish cast [Oodinium].

CONTRAINDICATIONS
This medication is not indicated for the treatment of fungal, bacterial, or viral infections of marine or freshwater fishes. The use of Kordon's Copper Tru is primarily recommended for the prevention and control of Oodinium ocellatum and Cryptocaryon irritans.

This product is not intended to be used as a medication or chemotherapeutic agent for food fish, as regulated by the U.S. FDA (Food and Drug Administration) or the U.S. EPA (Environmental Protection Agency).

Certain species of butterflyfishes and clownfishes may demonstrate a sensitivity to higher concentrations, which in the early stages can be reflected by a lack of appetite or complete cessation in feeding. In such cases, the copper concentration should be reduced, or the fish moved to another aquarium for individual treatment at a lower concentration.

Caution: Copper is highly toxic to most species of invertebrates.

Prevention or treatment of Oodinium ocellatum and/or Cryptocaryon irritants:
(a) Transfer all invertebrates to another holding tank. Remove activated carbon prior to treatment if applicable.
(b) Calculate the actual volume of water to be treated, taking into consideration the displacement of water by gravel, rock, coral, etc.
(c) Add 1 drop of Copper Tru solution per 1 gallon of water. This produces a concentration of 0.2 ppm. After adding Copper Tru wait 15 minutes for mixing and then test the water with a copper ion test kit to determine the copper concentration.
(d) Add subsequent doses only as necessary to bring the concentration up to the initial concentration. A partial water change (25% or more) before each use will ensure more effective results. A test kit is required to monitor the copper level. For example, if after performing a subsequent copper test, a result of 0.1 ppm is obtained, in the tank for which the volume is 10 gallons, you would add 5 drops of Kordon's Copper Tru solution. This addition would bring the concentration level back to 0.2 ppm. Note: The minimum copper ion concentration recommended for treatment is 0.15 ppm. In some parasitic infestations, it may be necessary to increase the copper concentration beyond the minimum dosage. Further additions should be made in increments of 0.01 ppm. For example, if an aquarium is treated with the minimum dosage of 0.2 ppm, and within 24 hours an improvement in the fishes condition is not observed, additional copper solution should be added to increase the concentration to 0.21 ppm. Copper Tru may be used up to 0.25 ppm maximum, if required. However, caution should be exercised (see Toxicity) when using concentrations higher than 0.25 ppm.
(e) At the conclusion of the treatment period, make a partial water change of up to 50% in order to remove any excess copper. Additional changes may be necessary. Add NovAqua or PolyAqua to detoxify residual copper. Continue to monitor the copper level. Invertebrates should not be returned to the tank until the copper concentration is below a level that is toxic to invertebrates (less than 0.05 ppm).

CAUTIONS
Copper is highly toxic to invertebrates. If treatment is carried out in an established aquarium, all invertebrates must be transferred to a separate facility.

The Merck Veterinary Manual (see http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/170404.htm) has the following about the use of copper ion in aquarium and pond conditions: Copper sulfate (CuSO4) is not approved by the FDA [U.S. Food & Drug Administration]; however, a number of compounds containing CuSO4 have been approved by the US Environmental Protection Agency (EPA) as
algicides for use in aquatic sites. CuSO4 is currently designated as"of moderate regulatory concern" and is used in food fish practice;
however, practitioners must keep themselves informed of possible changes in the status of this chemical. CuSO4 has been used for many
years as a parasiticide and is particularly useful in large production ponds because of its relatively low cost. Copper is highly toxic to fish, and safe use depends on its interaction with carbonate salts in water. In freshwater systems, the concentration of CuSO4 applied should be based on the total alkalinity (TA) of the water. If TA is <50 mg/L, copper cannot be used safely without performing a bioassay. If TA is 50-250 mg/L, a safe concentration of CuSO4 can be determined by dividing the TA by 100. For example, if TA = 100 mg/L, a safe concentration of CuSO4 would be 1 mg/L. If TA is >250 mg/L, the concentration of CuSO4 should not exceed 2.5 mg/L. Other concerns when treating a pond with CuSO4 (in addition to its direct toxicity to fish) relate to its algicidal activity. Rapid death of an algal bloom can precipitate a catastrophic oxygen depletion. Use of CuSO4 in ponds not equipped with supplemental aeration is risky. Use of CuSO4 is hazardous if a pond has a heavy algal bloom (secchi disc 18 in.) or if the water is already deficient in oxygen due to other factors, (eg, cloudy weather or high water temperature). CuSO4 is efficacious against most protozoal parasites, is economical, and despite these concerns, may be an excellent choice when multiple treatments are required (eg, in an epizootic of Ichthyophthirius multifiliis ). In saltwater systems, copper is sometimes applied in a chelated form because it stays in concentration longer. Chelated compounds may be difficult to use safely and require careful
monitoring. CuSO4 can be used to treat marine fish, but the concentration of active copper must be closely monitored (test kits
are available) and should be maintained at 0.2 mg/L for up to 3 wk. Safe and effective use of copper in marine systems requires that Cu2+
concentrations be tested at least once a day. Copper is extremely toxic to invertebrates, so these must be removed before the water is
treated. Copper is also toxic to plants and should not be used in ornamental ponds that have been stocked with valuable plants.
Finally, copper will impact bacteria in biofilters and a transient increase in ammonia should be expected for several days following
treatment. Monitoring ammonia until measurable concentrations subside is recommended.

Another useful article is "The Use of Copper in Freshwater Aquaculture and Farm Ponds" by Craig Watson and P.E. Ranong (see
http://edis.ifas.ufl.edu/FA008).