I have run a reef quarantine setup for two years and quarantined every fish and invert before it hit my 120 gallon display. Two outbreaks in my first year of reefkeeping taught me that quarantine is cheaper than a tank wipe. Here is the kit I would buy again, and the routine that works.
Quick gear comparison
| Gear | Purpose | Pick |
|---|---|---|
| Quarantine tank | 20 to 40 gallons, bare bottom | Aqueon 20 gallon Long |
| Sponge filter | Pre-cycled, no biomedia | AquaClear 30 sponge filter |
| Heater | 100 to 150 watts, controller-ready | Eheim Jager 150W heater |
| Med kit | Copper, prazi, formalin | Hanna Copper Checker |
| PVC hides | Stress reduction | PVC fittings starter kit |
1. The tank - 20 gallon long, bare bottom
A 20 gallon long gives you horizontal swim room without consuming half a closet. I run mine bare bottom because sand binds copper and complicates medication dosing. Cleanup is a single siphon pass. The Aqueon 20 Long has the right dimensions for a tang or large angelfish to acclimate in.
2. Filtration - sponge filter only
A pre-cycled sponge filter is the only biological filtration that survives a copper course. I keep a spare sponge in my sump at all times so quarantine is ready in 30 minutes when a fish ships. Hang-on-back filters with ceramic media get destroyed by copper and become useless.
3. Heater and temp control
A 150W Eheim Jager holds temperature in a 20 long without overshooting. I pair it with an inkbird controller to prevent stuck-on disasters. Quarantine temperature ramping is part of the protocol: 80 to 82 F speeds the ich lifecycle, shortening total treatment time.
4. Medication kit
The core stack: chelated copper for ich and velvet, praziquantel for flukes, and formalin for stubborn flukes if prazi fails. The most important purchase is a Hanna Copper Checker. Test strips lie about copper level and stripping out at 1.8 ppm versus 2.5 ppm is the difference between treatment and a dead fish.
5. Hides - PVC fittings
Stress drops disease defenses. A box of black PVC fittings gives every new fish three or four caves to choose from. Cheap, easy to clean, and they do not absorb copper.
My 6-week quarantine routine
- Week 1: Acclimate fish, observe for 7 days, no meds. Watch for flashing, white spots, rapid breathing.
- Week 2-3: Begin chelated copper ramp to 2.0 to 2.5 ppm over 4 days. Hold 14 days. Test copper daily with the Hanna.
- Week 4: Strip copper with cuprisorb or large water changes. Begin prazi 5-day course for flukes.
- Week 5: Observation, fresh water changes, food trials. Heavy feeding to put weight back on.
- Week 6: Final 7-day observation. If clean, transfer to display.
- Always quarantine inverts separately; copper is fatal to shrimp, snails, and corals.
How to set up your quarantine
- Keep the sponge filter in your display sump full-time so it stays cycled.
- Use white buckets and a dedicated siphon for quarantine to avoid contaminating the display.
- Photograph the fish on arrival. Photos reveal spots and erosion that look subtle in person.
- Buy one extra heater. Quarantine heater failures are the most common cause of stalled treatment.
- Write down your med schedule. Memory fails after a long day; a posted log does not.
Frequently asked questions
How long should new fish stay in quarantine?+
Four to six weeks. Two weeks is not long enough; many parasites cycle in 21 to 28 days, so shorter quarantines miss them.
Do I need to quarantine corals too?+
Yes. Coral quarantine for 76 days breaks the lifecycle of pests like AEFW and red bugs, even if the coral looks clean on arrival.