SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/fish-no-soap-cleaning

What should you never use to clean aquarium gear that goes back in the tank?

Soap or detergent, because it is harmful to fish.

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  1. Soap or detergent ✔
  2. Plain water
  3. A clean brush

Why: Soap residue is harmful to fish. Rinse tanks, gravel and decorations with plain water and scrub with a brush or cloth instead.

Huh, didn't know that: Purdue suggests plain non-iodized salt on a clean cloth for scrubbing aquarium equipment.

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What do you call a fish that can do magic? A spell-fish.
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References

Answer: Soap or detergent. Soap residue is harmful to fish. Rinse tanks, gravel and decorations with plain water and scrub with a brush or cloth instead.

  1. Purdue Extension 4-H-447-W: Aquatic Science www.extension.purdue.edu/4-H/_docs/4-h-447-w.pdf
    Never use detergent, since it is harmful to fish.
    Checked 2026-10-11.
  2. Texas A&M Extension: Gold Rush, A Kid's Guide to Goldfish Care extension.rwfm.tamu.edu/wp-content/uploads/sites/8/2013/10/Goldrush-%E2%80%93-A-Kid%E2%80%99s-guide-To-Goldfish-Care.pdf
    Rinse the aquarium, gravel, and any decorations very well (do not use any cleaners such as soap).
    Checked 2026-10-11.

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