Saltwater Fish Quarantine: SRQT Step-By-Step Guide
Any first time reefer could do this!
We developed this SRQT (Serious Reefs Quarantine) method so anyone can run a simple, effective, and safe saltwater fish quarantine at home. This guide walks you through the exact components we use to proactively prevent ich, velvet, brook, uronema, and flukes from ever making it into your display tank. If you want a practical, beginner friendly saltwater fish quarantine that is hard to mess up, read on!
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What SRQT Is and Why We Use It
SRQT is a proactive, three-component quarantine protocol that proactively treats for five common concerns: ich, velvet, brook, uronema, and flukes. We assume new arrivals have probably been exposed somewhere along the distribution chain, even if they show no symptoms. Rather than relying on visual observation alone, SRQT uses measurable, repeatable treatments that are easy to execute and hard to mess up.
Key design goals:
Safe for home use (no formalin)
Simple enough for beginners—if you can do a few 10 gallon water changes, you can do SRQT
Consistent medication concentrations by mixing one batch of water for the whole protocol
Measurable and testable where possible
Approved by professionals. Designed by Elliot Lim from Marine Collectors with consultation by Bobbly Miller (Humbelfish)
Pairs well with handpicking fish at your local fish store
Step 1: Prepare the medicated batch for ich and velvet
Goal: treat nonsymptomatic Ich and Velvet (the common invisible carriers) using tested, stable copper levels and clean water.
Mix one batch of quarantine water in a 55 gallon white Brute or similar bin. We do this once in a 55 gallon so salinity, temperature, and copper concentration stay consistent for every water change.
Salt choice: Instant Ocean. It is inexpensive, has lower calcium, alkalinity, and precipitation compared with reef salts. This helps preserve therapeutic copper levels over time.
Copper product: use Copper Power (chelated copper sulfate) and run it at 2.5 to 2.65 ppm. This is the range we recommend for the SRQT.
Test kit: use a Hanna Checker high range copper meter for accuracy. Test a few times initially to average any variance, then use the same batch for the entire protocol.
Temperature: heat the batch to 78°F plus or minus 2°F. This is a practical balance to keep parasite life cycles moving without stressing most fish.
Transport and tank: pour the first 10 gallons of medicated saltwater into a 10 gallon tank for quarantine. A 10 gallon volume pairs perfectly with a single 55 gallon batch to support the initial ten gallons as well as four 100% water changes from a single bin of water.
Equipment for the 10 gallon: airstone and pump for oxygen, an inexpensive heater, and a simple PVC hide sized to the fish. Do not use ABS (it floats). Avoid strong powerheads.
Water maintenance: perform 100% water changes with your premixed copper every 3 days for a total of four changes. Keep the tank filterless to avoid cross contamination and simplify execution.
This approach relies on three simple advantages: measurable copper, consistently clean water, and an easy single-batch setup so you never have to re‑dose or worry about medication fluctuation mid protocol.
If this is your first time quarantining fish, consider starting simple. Treat for Ich and Velvet using only the copper steps above. That alone puts you ahead of 80% of reefers. Once you’ve mastered that, add the Brook, Uronema, and Fluke treatments below to join the top 1% who proactively prevent all five parasites with minimal effort.
Biofilter Note: Ammonia is managed through the four 100% water changes. For this reason, the method works best with one or two fish at a time, and it’s important not to overfeed. Count the pellets—about five per day is adequate for most fish. If you need to quarantine multiple fish at once, consider using multiple tanks or adding established plastic biofilter media to the QT tank. Plastic is ideal because it won’t absorb copper the way other bio-media can.
Step 2: Treat for Brook and Uronema with Metronidazole
Goal: proactively eliminate brook and uronema exposures using a safe, user friendly alternative to formalin. Step two is designed be done simultaneously with step one.
Product: MetroPlex (metronidazole formulation) is the SRQT choice because it is widely available, safe to use in the home, and difficult to overdose.
Dosage: two scoops using the provided measuring spoon (follow package directions). Add as directed to the 10 gallon quarantine tank.
Frequency: dose every 48 hours directly to the QT tank. For higher risk species like wild clownfish, dose every 24 hours.
Alternative pro option: USP metronidazole powder measured with a gram scale offers more precise dosing if you want to advance your practice.
Note: Don’t worry if a 100% water change removes the metronidazole from the tank. When treating non-symptomatic Brook and Uronema proactively, it’s not necessary to maintain constant therapeutic levels. Since the half-life of metronidazole is about 24 hours, try to dose it at least a 24 hours before your planned water change.
Why MetroPlex For Brook and Uronema prevention?
MetroPlex is reasonably effective for non-symptomatic infections and is widely available at pet stores and online. If you want to use a pure USP metronidazole powder, that is an advanced option requiring a gram scale and adjusted dosing.
Formalin is a stronger option and what many professional QT services use but is carcinogenic, much harder to acquire, and we do not believe is appropriate for new hobbyist use.
Step 3: Remove flukes with two PraziPro baths
Goal: Treat both symptomatic and nonsymptomatic external flukes using two controlled praziquantel baths. Step three is designed be done simultaneously with step one and two.
Setup: use a graduated, translucent 5 gallon bucket (paint buckets with gallon marks work great) so you can easily measure volume.
Water: prepare 4 gallons of Instant Ocean at 1.025 salinity and heat to tank temperature.
Product and dose: PraziPro dose is 3 mL per 4 gallons. Use a 3 mL syringe to measure and add the product.
Aeration and heat: run an airstone and small heater in the bucket so the water stays oxygenated and within temperature range.
Timing: perform a six hour PraziPro bath when the fish first arrives (before it ever goes into the quarantine tank). Repeat a second six hour bath on day 6 when you do the second 100% water change.
Pro option: Praziquantel powder and a gram scale can be used for more precise dosing if desired.
Why PraziPro? PraziPro is effective, safe with most fish, widely available, and easy to use
Note: PraziPro’s label recommends a much lower dose because it’s designed for direct tank treatment over an extended exposure period. The SRQT method instead uses a 6-hour bath at a therapeutic concentration of 7.5 mg/L, which aligns with common practice among the advanced quarantine community.
Step 4: How this SRQT fits into the bigger picture
We built this saltwater fish quarantine to be safe and practical for home use. A few important contextual points:
No formalin: Formalin is effective but carcinogenic and not appropriate for home use. We replaced it with metronidazole for brook and uronema, and PraziPro for flukes.
Designed for beginners: you do not need multiple tanks, complicated sterilization, or precision microbiology skills. If you can do four 100% water changes and basic dosing, you can run SRQT.
Low hardware: no filter is required in the 10 gallon quarantine tank. That reduces setup, risk of cross contamination, and ongoing maintenance.
Pairs well with local sourcing: buying from your local fish store and hand inspecting fish before purchase dramatically increases success. This SRQT then protects your display even further.
Backed by field experience: we developed SRQT alongside experienced quarantine professionals so it balances safety, accessibility, and effectiveness.
“An ounce of prevention is worth a pound of cure”
What we are not recommending and why
There are other quarantine approaches you may hear about. Here is why we selected the SRQT instead:
Visual-only observation can miss carriers. Many parasites are invisible until they break out. Proactive medicated quarantine prevents outbreaks in your display tank.
Tank transfer method (moving fish between two tanks on a tight schedule) can work but requires two complete rigs, perfect timing, strict biosecurity, and zero cross contamination risk. It is a nuanced method better suited to very experienced hobbyists.
Chloroquine phosphate and other meds often need gram scales, biodegrade, lack simple test kits, and have limited availability. They can be effective but are harder for a beginner to measure and control.
Formalin is the gold standard for some parasites but it is carcinogenic and not appropriate for home use. We purposely designed SRQT to avoid it.
Saltwater Fish Quarantine FAQ
How long is the SRQT quarantine period?
The protocol runs for about 14 to 15 days. You perform 100% water changes every 3 days for four total changes, with the final transfer or isolation taking place on day 14 or 15.
Do I need a filter on the quarantine tank?
No. The SRQT uses frequent 100% water changes instead of a biological filter. This removes the need to have a functional second biofilter for QT on hand at all times. Maintaining established biofilters can be a major preventive for newer reefers.
100% water changes keeps the water exceptionally clean. It removes organic waste, stress hormone, cortisol, and other unknowns from the QT water. Fish just do better in clean water.
If you are quarantining multiple fish at once of fish that require heavy feeding you can use an established biofilter on a SRQT tank. Use one that has a plastic biomedia because plastic does not absorb or reduce therapeutic copper levels the same way other medias do.
Can I use different brands of copper, metronidazole, or praziquantel?
We recommend the specific products in this guide for reliability and predictable behavior. Pro alternatives exist (USP powders measured by gram scale), but those require more advanced skill and equipment. If you choose alternatives, research dosing and testing carefully.
Why Instant Ocean and why a white bin?
Instant Ocean has lower precipitation than some reef salts, which helps maintain copper levels. A white bin makes it easier to see any precipitation and to mix/monitor clarity during the batch preparation.
What if a fish shows visible disease before quarantine?
While often similar, visible disease may require different or stronger treatments and is outside the scope of this nonsymptomatic prophylactic SRQT. In those cases, follow species-specific guidance or consult experienced quarantiners for outbreak treatment options.
Can I reuse the 55 gallon medicated batch for multiple fish?
Yes, as long as you maintain copper levels and the water remains clean you can use the same batch for the protocol's water changes. Dispose and start a fresh batch if the batch becomes visibly dirty or if you finish the protocol cycle.
Saltwater fish quarantine does not need to be complicated. SRQT gives you a tested, safe, and beginner friendly path: one consistent medicated batch for ich and velvet, simple MetroPlex dosing for brook and uronema, and two PraziPro baths for flukes. Follow the steps consistently, use reliable test tools, and pair this protocol with smart sourcing from your local fish store for best results.
Acknowledgments
Thank you to Bobbly Miller (Humblefish) and Elliot Lim from Marine Collectors for sharing their knowledge with the SR community.
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