Ionic Copper Solution for PROFESSIONAL USE Overview For use by experienced, qualified professional aquarists only. Ionic, non-chelated copper solution. 1 drop per gallon of water increases free copper concentration by ~0.20 ppm. For use in fish-only aquaria. Not for use with scaleless fish. Not for use in aquaria housing live plants or invertebrates. Consult an appropriate reference source for the use of ionic copper solutions in aquaria before use.