What kind of Ick medicine? Certain kinds kill bacteria and some only target parasites. If it targets only parasites, you don’t have to remove your filter, if it targets bacteria as well, it will kill the nitrogen fixing bacteria in your filter. In the latter case, leave your filter off the tank as long as the medication is in use. Email me if you have any questions.

Nosoop4u

depends on the meds, you shouldnt have to tuern it off, id just remove the activaited carbon. The carbon will remove the meds. keep em out for a few days.

What kind of filter?
If the filter media is already in the water, then the medication will kill the beneficial bacteria in the filter regardless of whether it is on or off. So leave it on and monitor your cycle.

If the filter is outside of the tank then leave it off for the duration of the treatment and add an airbubbler to the tank to keep oxygen in the water for the fish.

Treat for ich for at least a week after you see the last spot fall off the fish. Next time you have ich, don’t use harsh medications, just use salt and warm water.

You shouldn’t have the filter off, only remove the carbon from the filter (the carbon will absorb the medication). Treatments usually lasts 10-14 days, or at least 3-5 days after you no longer see spots on the fish. If you stop treatment too early, the fish can be reinfected. This is because the parasites are protected inside a cyst on the fish and aren’t affected by the medication. It’s only when the cyst bursts and they’re released into the water that they can be killed.

Raising the tank temperature (slowly) can also help out by speeding up their lifecycle, so they drop of the fish sooner.