Editorial Policy
Last updated September 26, 2026
Sources
Numbers on this site come from primary or expert sources whenever possible, in roughly this order:
- Peer-reviewed research (with a link or DOI).
- U.S. government agencies such as the EPA and USGS.
- University extension services such as UF/IFAS and the Southern Regional Aquaculture Center (SRAC).
- Veterinary references such as the Merck Veterinary Manual, and databases such as FishBase.
- Manufacturer documentation, only for that manufacturer's own product (for example, dosing instructions).
Each figure in a guide's key figures table links to a numbered source at the end of the page. We open every link, or resolve every DOI, before publishing.
Fact, estimate or inference
We label figures as one of three types:
- Stated by source: the source says it directly.
- Our calculation: we computed it from sourced inputs, and we show the formula.
- Our inference: our reasoning from the evidence. Treat it as an informed opinion.
Much aquarium research comes from aquaculture or from species other than the ones in your tank. When we apply it to home aquariums, we say so.
Units
Gallons and °F come first, with liters and °C in parentheses. "Gallon" means the U.S. gallon (3.785 liters).
Reviews and updates
Each guide shows a "Last reviewed" date. We change that date only after rechecking the sources and figures, not after cosmetic edits.
Corrections
If you find an error, email hello@goodfishtank.com with the page and the source that contradicts it. We fix confirmed errors and update the review date.
Money and independence
The site earns money from display ads and affiliate links. Neither decides what we recommend. See the affiliate disclosure.
Not veterinary advice
These guides are general information. For a sick fish that doesn't respond to basic care, contact a veterinarian who treats fish.