Remove all invertebrates from the tank as well as any chemical filtration. Use 5mL (1 capful) of ParaGuard for every 40L (10 US gallons). Repeat this dose daily as required as long as fish show no stress.
ParaGuard can also be used as a medicated dip. For 1 hour dips, use 3mL per 4 L (1 US gallon) in a container separate from your main tank. Dips may be extended if the fish show no evidence of stress. Keep in mind that many diseases linger in the water as well as on the fish. Giving a fish a dip treatment does no good if they go right back into infected water.
This is a tank set up in order monitor and medicate new fish before they go into the main tank. ParaGuard is gentle enough to use prophylactically (without visible symptoms) if needed. Quarantine times vary, but we generally recommend 2 weeks of treatment with ParaGuard to clear out any possible external infections.
Some fish are more sensitive to medications than others. Eels, loaches, rays, sharks, and many others are well known for their sensitivity to all kinds of medications. If you suspect that your fish may be sensitive to medications, it is just fine to start with a partial dose and build up to the full dose over several days.