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Aquarium Stocking Calculator

Check if your aquarium stocking level is safe.

Stocking Calculator

Check if your aquarium stocking level is safe

Formula

1 inch of fish per gallon of water (guideline)

How to Use

  1. 1
    Enter tank volumeInput your aquarium volume in gallons or liters.
  2. 2
    Select filtration typeChoose your filtration strength — basic, moderate, or heavy filtration.
  3. 3
    Add your fishEnter the number and approximate size of fish you plan to keep.
  4. 4
    Check stocking levelReview the stocking percentage and recommendations for a healthy tank.

Frequently Asked Questions

What is the one-inch-per-gallon rule?

The old rule suggests 1 inch of fish per gallon, but it is inaccurate for large or messy fish. Our calculator uses bioload-based calculations for better accuracy.

How many fish can I put in a 10 gallon tank?

A 10-gallon tank works for about 6-8 small fish (neon tetras, guppies). Avoid large or territorial species in small tanks.

What happens if I overstock my tank?

Overstocking leads to poor water quality, stress, disease, and shortened lifespans. Ammonia and nitrite spikes become more frequent.

Does filtration affect stocking capacity?

Yes. Heavy filtration with good biological media can support a slightly higher bioload, but tank volume remains the primary limiting factor.