Ich: symptoms and treatment

Symptoms

• white spots the size of salt grains on the body and fins,
• rubbing against rocks and decor,
• clamped fins, lethargy, fast breathing (when the gills are affected).

Why the spots come back

The parasite develops in stages. A spot on the fish is protected by its skin and medication can't reach it. When it matures it drops off, divides on the substrate into hundreds of new parasites, and these swim in search of a fish. Treatment only works on this free-swimming stage, which is why it takes several days and must continue after the last spot is gone.

Treatment step by step

1. Use an ich treatment from an aquarium shop, exactly as instructed and for the real amount of water (volume calculator).
2. Remove activated carbon from the filter during treatment, as it absorbs medication.
3. If your fish tolerate it, raise the temperature by 1 °C a day to about 28–29 °C (82–84 °F): the parasite's cycle speeds up and treatment is shorter.
4. Increase aeration: warm water holds less oxygen.
5. Keep treating as instructed for a few days after the spots disappear.

Shrimp and snails are sensitive to many medications. Move them for the treatment or choose a product labelled safe for them. If fish don't respond, consult a vet who treats fish.

Prevention

• Keep new fish in a separate quarantine tank for 2–4 weeks.
• Avoid sudden temperature changes, including during water changes.
• Keep the water clean: regular water changes and no overfeeding.

How Aquarium Monitor helps

An alarm for temperature changing too fast warns you about the situation that most often triggers ich. The “what I see” wizard takes recently added fish and temperature swings into account, and the app supports separate tanks, such as quarantine and hospital tanks, with their own treatment records.