Seachem Cupramine is a copper-based over-the-counter aquarium treatment used primarily for marine ich (Cryptocaryon irritans) and marine velvet (Amyloodinium ocellatum). It is a therapeutic ionic copper formulation designed to provide effective parasite control at concentrations tolerable to most scaled marine fish. Cupramine is not a prescription-grade veterinary medication; it is a hobbyist product that requires careful copper test monitoring to stay within the therapeutic window. Because copper is lethal to invertebrates and corals, Cupramine must only be used in a bare-bottom hospital or quarantine tank — never in a reef display. For valuable fish or complex systems, consult an aquatic veterinarian.

Overview

Copper has been a mainstay treatment for marine parasitic diseases for decades. Ionic copper interferes with parasite respiration and metabolism, killing free-swimming stages of Cryptocaryon and Amyloodinium. Cupramine uses a complexed copper system that is less toxic to fish than traditional copper sulfate while remaining effective against parasites. The therapeutic concentration is narrow — typically 0.35 to 0.5 ppm — and accurate testing with a copper test kit is essential.

Uses

  • Marine ich (Cryptocaryon irritans)
  • Marine velvet (Amyloodinium ocellatum)
  • Brooklynella (clownfish disease) at reduced effectiveness compared to formalin
  • External protozoan parasites in marine systems
  • Quarantine protocols for new marine fish

Dosage

  • Target concentration: 0.5 ppm (mg/L) total copper
  • Initial dose: Add half the total dose, wait 48 hours, then add the remaining half to reach target
  • Duration: Maintain therapeutic level for at least 14 days to cover the full parasite lifecycle
  • Testing: Use a dedicated copper test kit (Seachem MultiTest Copper recommended for Cupramine) every 1 to 2 days to confirm level

Follow the product label for exact milliliters per gallon. Consult an aquatic veterinarian for species-specific guidance.

Safety Considerations

  • NEVER use in reef tanks — Copper is absorbed by live rock, substrate, and sand and cannot be fully removed. A single dose in a display tank can render it permanently unsafe for invertebrates.
  • Lethal to all invertebrates — Shrimp, snails, crabs, corals, anemones, starfish, and sea urchins. Remove all invertebrates before treatment or treat only in a dedicated quarantine system.
  • Scaleless and sensitive fish — Some fish including certain wrasses, puffers, lionfish, and many elasmobranchs (sharks and rays) are sensitive to copper. Check species tolerance before treatment.
  • Marine angelfish and tangs — Generally tolerate copper but should be monitored closely for appetite loss or behavioral changes.
  • Regular testing required — Copper levels drift over time as copper is absorbed or bound by substrate and filtration. Without testing you cannot maintain the therapeutic window.
  • Do not combine with Seachem Prime or other ammonia binders, as they may interact with the copper complex. Seachem specifically warns against combination with reducing agents.

Water Chemistry Effects

  • Does not significantly affect pH, salinity, or hardness
  • Can be partially removed by activated carbon, cuprisorb, or Seachem PolyFilter after treatment
  • Copper binds to calcareous substrate and live rock — do not use in systems with these materials
  • Biological filtration may be affected, so monitor ammonia and nitrite during treatment

How to Use

  1. Set up a bare-bottom quarantine or hospital tank with plastic decor only (no rock or substrate)
  2. Remove activated carbon and any copper-binding media from the filter
  3. Calculate total tank volume accurately
  4. Add half the calculated dose
  5. Wait 48 hours and test copper level
  6. Add the remaining dose to reach 0.5 ppm
  7. Test copper level daily or every other day and top up as needed
  8. Maintain therapeutic level for a minimum of 14 days
  9. After treatment, remove copper with carbon, Cuprisorb, or large water changes before returning fish to display

FAQs

Can I use Cupramine in a reef tank? No. It will kill all invertebrates and permanently contaminate live rock.

What test kit should I use? Seachem MultiTest Copper is specifically calibrated for Cupramine’s complexed copper. Generic copper kits may read incorrectly.

Is it safe for all marine fish? Most scaled marine fish tolerate Cupramine at therapeutic dose, but some species are sensitive. Research your specific fish before treating.

Can I use it in freshwater? Freshwater ich is generally treated with formalin/malachite green (Ich-X). Copper can be used in freshwater but Cupramine is primarily marketed for marine use.

How do I remove copper after treatment? Use activated carbon, Seachem Cuprisorb, or PolyFilter. Large water changes also help. Test to confirm copper has dropped below 0.02 ppm before introducing invertebrates.