Why Quarantine? The 4 Big Wins

1. Stops spread: Isolation prevents pathogens from reaching your main tank.
2. Precision dosing: Smaller volume = accurate medication, less waste, lower cost.
3. Clear observation: Bare-bottom and minimal décor make symptoms visible.
4. Biofilter protection: Antibiotics can suppress nitrifiers; keep your display safe.

Stock your hospital cabinet with trusted aquarium antibiotics so you’re ready when symptoms appear: Amoxicillin (Fish Mox®), Ciprofloxacin (Fish Flox®), Doxycycline, Azithromycin, Cephalexin (Fish Flex®), Clindamycin, Penicillin, Sulfa, Metronidazole (Fish Zole®), Fluconazole.

Who Should Quarantine—and For How Long?

• Sick fish: Immediately move to quarantine for diagnosis and treatment.
• New arrivals: Quarantine for 2–4 weeks to screen for hidden issues.
• Returning travelers (shows/breeding): Re-quarantine after events.

Consistency here prevents most outbreaks. Think of quarantine as cheap insurance for your display tank.

Core Hardware

• Tank: 10–20 gal (freshwater) / 20–40 gal (saltwater, larger species). Bare-bottom for easy cleaning.
• Heater & thermometer: Stable temperature reduces stress and speeds recovery.
• Filtration: Air-driven sponge filter—gentle, oxygenates, and easy to seed.
• Aeration: Air stone—especially crucial when dosing antibiotics.
• Cover/lid: Keeps jumpy or stressed fish safe and reduces evaporation.
• Lighting: Dim, adjustable. Low light calms fish; bright light for quick exams only.

Water Tests & Dedicated Tools

• Liquid test kit: ammonia, nitrite, nitrate, pH; add salinity for marine.
• Separate nets, siphon, towels, and buckets (never cross-use with display tank).
• Water conditioner and buffer for stable parameters.
• Measurement tools for dosing (mg scale or accurate spoons).

Medication Cabinet (Ornamental Fish)

Keep a small, fresh stash for emergencies (check dates):

• Amoxicillin (broad-spectrum)
• Ciprofloxacin (gram-negative)
• Doxycycline (mixed infections)
• Metronidazole (internal/external anaerobes, protozoa)
• Azithromycin (stubborn cases)

1. Rinse & place: Position the tank on a sturdy, level surface away from drafts and sunlight.
2. Water & heat: Fill with dechlorinated water; match temperature and pH to the display tank.
3. Seed the sponge filter: If possible, squeeze media from a healthy, established filter over the sponge to jump-start bacteria.
4. Add aeration: Install air stone; set gentle flow to avoid exhausting weakened fish.
5. Minimal décor: PVC elbows or inert caves for security; avoid gravel/sand for easy waste removal.
6. Stabilize: Run the system for an hour; confirm heater and airflow are steady.
7. Test baseline: Ammonia 0, nitrite 0, nitrate <20 ppm (FW). For marine, set salinity to match source tank.

Drip Acclimation (Recommended)

1. Float bag 10–15 minutes to equalize temperature.
2. Open into a clean bucket; start a siphon from quarantine tank to the bucket (knot tubing for 2–4 drips/sec).
3. Acclimate 20–40 minutes; discard shipping water; never add it to the hospital tank.
4. Net fish gently into quarantine; cover the tank and dim lights.

The First 24 Hours

• Lights low; no handling; offer a small, high-quality meal only if fish shows clear appetite.
• Test ammonia/nitrite after 6–12 hours; be ready for a small water change if needed.
• Begin written observation notes (behavior, respiration, external lesions).

Quick Symptom Grid

• Bacterial — red streaks, ulcers, ragged fins, cloudy/bulging eyes, pineconing (dropsy).
• Fungal — cotton-like tufts, white fuzzy patches.
• Parasitic — flashing, white spots (ich), rapid gilling without bacterial signs.
• Water quality — gasping at surface, clamped fins, lethargy after parameter swings.

When Antibiotics Make Sense

Use antibiotics only for suspected bacterial disease. Keep a targeted arsenal from credible sources: Amoxicillin, Ciprofloxacin, Doxycycline, Cephalexin, Metronidazole.

Typical Outline (Adjust to Species & Label Directions)

1. Antiparasitic (non-antibiotic): e.g., praziquantel (per label).
2. Broad-spectrum antibiotic (only if warranted): e.g., Doxycycline or Amoxicillin.
3. Supportive care: vitamins, probiotic foods post-course.

Use this approach thoughtfully; don’t medicate healthy fish without cause. Observation first, meds second.

Calculate True Water Volume

Length × Width × Water Height (in inches) ÷ 231 = gallons. Subtract 10–15% for décor/PVC.

Typical Course Lengths

• Amoxicillin: follow label (commonly 7–10 days)
• Ciprofloxacin: per label (often daily renewal with partial changes)
• Doxycycline: per label (commonly 5–7 days)
• Metronidazole: per label; baths or food depending on target

Shop options: Amoxicillin, Ciprofloxacin, Doxycycline, Metronidazole.

Redosing Logic After Water Changes

If you change 30% of water mid-course, replace 30% of the dose to restore target concentration.

Targets & Schedule

• Ammonia: 0 ppm (detoxify immediately if detected; then change water).
• Nitrite: 0 ppm; nitrate <20 ppm.
• Temp/pH: stable, species-appropriate.

Filtration Rules While Dosing

• Remove carbon/chem media (they strip meds).
• Use air-driven sponge for O₂ and gentle biofiltration.
• Increase aeration during courses with heavy oxygen demand.

Route Selection

• Medicated food for internal infections if fish are eating (pair with Doxycycline or Azithromycin per label).
• Baths for external lesions (e.g., Ciprofloxacin per label directions).
• Dips short, concentrated contact for stubborn patches (e.g., Metronidazole).

Plan

• Small, frequent offerings; remove leftovers promptly.
• Soak pellets with dissolved medication (per label) when using oral routes.
• Boost with vitamins; consider garlic for appetite support.

If Fish Won’t Eat

Switch to baths/dips while stabilizing stressors (flow/light/cover). Reassess diagnosis if anorexia persists.

Use This Daily Template

Date:
Temp:   pH:   NH3:   NO2:   NO3:
Medication & Dose:
Feeding Response:
Behavior Notes:
Lesions/Fins/Eyes:
Water Change %:
Next Action:  

• Dim lights; use a dark backing on two sides.
• Gentle flow; avoid blasting weakened fish.
• Provide inert hides (PVC).
• Handle only when necessary.

Positive Signals

• Reduced redness, better fin edges, appetite returns, calmer breathing.

Red Flags

• No improvement, worsening lesions, persistent anorexia, water parameter instability.

If needed, consult an aquatic professional and consider switching from, say, Amoxicillin to Ciprofloxacin per label guidance.

Completion Checklist

• Finish full labeled duration, even after symptoms improve.
• Large water change (40–50%) post-course; reintroduce carbon to strip residues.
• Begin probiotic/immune support foods during recovery phase.

• Gravel-vac bare bottom; remove detritus and uneaten medicated food.
• Run carbon 24–48 hours; then remove before any future course.
• Re-seed sponge as needed; monitor for mini-cycles.

• 7+ days symptom-free after finishing antibiotics.
• Normal appetite, activity, and respiration.
• Stable water tests for a full week.

Reintroduction

Match temp/pH; slow drip if parameters differ. Dim lights; observe closely for 48–72 hours.

• Label nets, siphons, and buckets “QT” vs. “Display.”
• Disinfect with appropriate solutions; air-dry fully between uses.
• Wash hands/tools between tanks; don’t share towels.

Marine Notes

• Match salinity precisely; avoid rapid SG changes.
• Remove copper/reef additives when using antibiotics.
• Isolate inverts; most hospital tanks are fish-only.

• Spare sponge filter (kept seeded), air pump, airline, valves.
• Heater, thermometer, lid, small light with dimmer.
• Liquid test kit; water conditioner; buffers.
• Dedicated nets/siphon/buckets; PVC hides.
• Core antibiotics from FishAntibiotics.us: Amoxicillin, Ciprofloxacin, Doxycycline, Cephalexin, Metronidazole, Azithromycin.

• Set up QT tank (heated, aerated, seeded sponge, bare-bottom).
• Acclimate gently; dim lights; reduce stress.
• Observe & log; diagnose before dosing.
• Select one appropriate antibiotic (if bacterial) from FishAntibiotics.us; follow label directions.
• Test daily; partial water changes; precise redosing.
• Finish full course; post-course water change; run carbon 24–48h.
• Recovery nutrition + probiotics; monitor 7+ days symptom-free.
• Reintroduce slowly; keep tools separate; disinfect.