How long should a quarantine treatment last?

It depends on the parasite or pathogen lifecycle. Ich and velvet treatments must outlast the parasite's free-swimming stage and typically run two to three weeks past the last visible spot, while bacterial and fungal courses follow the medication label. The calculator sets a disease-appropriate length.

Why does a water change come before re-dosing?

Most fish medications instruct a partial water change before the next dose to remove spent medication and waste, preventing overdose accumulation. The schedule places a water change on the correct days so each fresh dose starts from a known baseline.

How are doses scaled to my tank?

Medication labels give a dose per unit of water, commonly per gallon. The calculator multiplies that per-gallon dose by your tank volume so the schedule shows the actual amount for your tank rather than a generic figure. Always confirm against your product label.

Is this a substitute for the medication instructions?

No. It is a planning aid that builds a sensible rotation and reminds you when to dose and change water. Always follow the specific medication's printed instructions and a vet's advice, since active ingredients and concentrations vary between brands.

Should the quarantine tank have a heater?

Yes for ich and velvet — raising temperature speeds the parasite lifecycle so treatment clears faster, but only within the fish's safe range and with strong aeration since warm water holds less oxygen. The schedule notes temperature steps where they apply.

Aquarium Quarantine Tank Protocol Calculator

A quarantine tank only works if you dose and change water on the right days for the specific disease. This calculator builds a day-by-day rotation — dosing days, water changes, and observation periods — scaled to your tank volume and matched to the pathogen you are treating.

How it works

Each disease has a treatment length and a dosing interval tuned to its lifecycle. The schedule is generated as:

for day = 0 to treatmentDays:
  if day mod doseInterval == 0:  water change (except day 0) → then dose
  dose amount = perGallonDose × tankGallons
  observe daily; extend if symptoms persist

A partial water change precedes each re-dose to clear spent medication, so doses never accumulate to a toxic level. Doses are scaled by multiplying the per-gallon figure for the disease by your tank volume, giving the actual amount to add.

Example and tips

A 10-gallon QT treating ich runs a roughly two-week course with re-dosing every other day after a 25 percent water change, plus a raised temperature to speed the parasite’s free-swimming stage where the fish tolerate it. Always run strong aeration during treatment — many medications and warm water both lower dissolved oxygen. Treat this schedule as a plan and confirm every dose against your specific product label and, for valuable fish, a vet.