🐟 How to Maintain a Hospital Tank for a Sick Fish
When your fish gets sick, setting up a hospital (or quarantine) tank is the first step toward recovery. But keeping that tank safe and stable during treatment is just as important as choosing the right medication.
In a hospital tank, your main goals are simple: control ammonia spikes and maintain consistent medication levels — without adding stress to your fish.
Why Hospital Tank Maintenance is Tricky
Most medications disrupt or kill beneficial bacteria, which means your normal filtration can’t fully protect your fish from ammonia. On top of that, frequent water changes — necessary for keeping the water safe — dilute the medication. That’s why you need a routine that balances both.
My Step-by-Step Hospital Tank Routine
Morning
Check water temperature and equipment
Test ammonia (and nitrite if the fish will be in treatment for a week or more)
Remove waste and uneaten food
Observe your fish closely for changes in breathing, swimming, or appetite
Evening
Feed lightly — no leftovers allowed
If ammonia or nitrite is above safe limits, perform a partial water change (25–50%)
Redose medication in proportion to the water replaced
Log your test results, water change percentage, and medication dose
Weekly / End of Treatment
Large water change to remove medication residue
Run activated carbon (if safe for the fish and meds used)
Disinfect tank and equipment before storage
The Key to Consistency: A Written Log
It’s easy to lose track of doses and water changes when you’re focused on your fish. That’s why I created The Tank Lady Hospital Tank Daily Maintenance Checklist — a one-page printable you can tape near your tank. It includes:
A morning, midday, and evening routine
A quick reference table for ammonia and nitrite triggers
A 7-day log for tracking parameters, water changes, and medications
📄 Download Your Free Printable
Click here to get the PDF checklist — just fill out the short form and it’s yours.
Whether you’re treating ich, fin rot, or something more mysterious, this checklist will help you keep your fish’s temporary home as safe and stable as possible during recovery.
💬 Have you had to run a hospital tank before? Share your experiences in the comments — your tips might help another fish keeper save their pet.