One rule sits above the rest: nothing on this site is written from memory. Every specification is quoted from a document we link, every recommendation is arithmetic we publish, and where neither exists the page says so instead of filling the gap.
Sourcing
- Specifications come from the manufacturer, or from a retailer listing that states a kit's contents. The link is at the foot of the page that uses it, every time.
- Unpublished figures stay unpublished. If a maker does not state a flow rate, we do not estimate one. Bundled kit filters and air-driven sponge filters are the routine cases, and we say so on the page rather than quietly filling in a plausible number.
- Biology is cited, not asserted. Ammonia toxicity, the nitrogen cycle and the pH and temperature relationship are sourced to public documentation on the pages that rely on them.
- Where a source contradicts another source, the page says which one it followed and why, rather than silently picking the convenient figure.
What is never published here
- Testimonials or user reviews. We have no verified reader accounts to publish, so there is no testimonials section anywhere on this site and never will be until there is something real to quote.
- Claimed first-hand testing. We have not used these products. Every product page says so on the page.
- Scores, stars or ratings — on the page or in the structured data. A score summarizes testing; ours would summarize nothing.
- Invented credentials. No certifications, no expert panel, no "medically reviewed", no veterinary board.
- AI-generated filler. Pages exist because a real search question needs answering. Where the honest answer is short, the page is short.
- Prices from memory. Prices come from a live feed and expire after 48 hours, after which the figure disappears rather than going stale on the page.
How recommendations are made
By arithmetic that is published before it is applied. Filters are judged against the rated flow their intended tank size needs once real-world throughput loss is accounted for; heaters against the wattage required for the reader's coldest realistic room temperature rather than an average one. The formulas, with worked examples, are on how we pick.
The point of publishing the method is falsifiability. If a pick here is wrong, you can identify the step where we went wrong instead of having to take our word for the conclusion.
Every roundup also names at least one product not to buy first, and explains why. That includes products we earn a commission on. A shortlist where every item is recommended is a catalog with a headline on it.
Commercial independence
The site is funded by Amazon Associates commissions, set out in full on the affiliate disclosure. No brand has paid for a placement, a position or a line of copy; no brand has seen a page before it published; no free or discounted product has been accepted; and no sponsored or guest content is published.
Where a manufacturer's own store would serve the reader better than Amazon — better price, better stock, better warranty — we say so, including when it earns us nothing. Buyer first is not a slogan here, it is the only thing that makes a commission-funded site worth reading.
Corrections
Errors get fixed rather than quietly edited away. If a specification here contradicts the manufacturer, or the arithmetic on a page does not hold, tell us and we will correct the page and note that it changed. Every page carries a visible "last updated" date so you can tell how current what you are reading is.
Corrections, and anything else: info@finandfilter.com or the contact page.
Who writes this
One person, named on the about page, framed accurately as an enthusiast rather than as an expert. There is no editorial team, and inventing one to look more substantial would break the first rule on this page.
Health and safety
Nothing here is veterinary advice. Where a fish is visibly ill rather than stressed by water quality, we say to consult an aquatic vet or an experienced local shop instead of guessing from a description. Where a step carries a real hazard — electrical safety around water, ammonia handling for a fishless cycle — the page states it at the point the reader would meet it, not in a disclaimer at the bottom.