# Fin & Filter

> The first tank that doesn't kill fish. Freshwater aquarium guidance for first-time fishkeepers, built on published manufacturer specifications and arithmetic we print in full.

Fin & Filter is an independent US publisher covering freshwater home aquariums for first-time fishkeepers. The site is organized as the five steps that decide whether a beginner's fish survive: choosing the tank, sizing the filter, cycling the water, stocking it, and maintaining it.

The site's central argument is that most first fish die from one omission: the tank was never cycled. A new aquarium filter contains none of the nitrifying bacteria that convert fish waste into something harmless, so ammonia accumulates from day one. Growing that colony takes roughly four to six weeks.

## What we do

We publish 38 guides across five hubs, plus the arithmetic behind every gear recommendation. Every specification is quoted from a manufacturer document or retailer listing that is linked on the page. We have not tested the products we recommend and we say so on every page — what we publish instead is the calculation, so any reader can re-run it.

## Start here

- [Start here: your first tank, step by step](https://finandfilter.com/start-here): the whole first month in ten steps, in order.
- [How we pick](https://finandfilter.com/how-we-pick): the filter turnover and heater wattage formulas, with worked examples and sources.
- [How to cycle a fish tank](https://finandfilter.com/cycling/how-to-cycle-a-fish-tank): the step that decides whether the fish live.
- [Frequently asked questions](https://finandfilter.com/faq): twenty common beginner questions, answered briefly.

## The five hubs

- [Tanks, Kits & Gear](https://finandfilter.com/starter-kits) (Step one, 8 guides)
- [Filters & Filtration](https://finandfilter.com/filters) (Step two, 9 guides)
- [Cycling & Testing](https://finandfilter.com/cycling) (Step three, 6 guides)
- [Stocking & Fish](https://finandfilter.com/stocking) (Step four, 7 guides)
- [Water Care & Maintenance](https://finandfilter.com/water-care) (Step five, 8 guides)

## All guides

### Tanks, Kits & Gear

- [The best aquarium starter kits for beginners](https://finandfilter.com/starter-kits/best-aquarium-starter-kits)
- [The best 10 gallon aquarium kits](https://finandfilter.com/starter-kits/best-10-gallon-aquarium-kits)
- [The best aquarium heaters for a first tank](https://finandfilter.com/starter-kits/best-aquarium-heaters)
- [10 gallon vs 20 gallon: which should your first tank be?](https://finandfilter.com/starter-kits/10-gallon-vs-20-gallon-first-tank)
- [Aqueon vs Tetra starter kits](https://finandfilter.com/starter-kits/aqueon-vs-tetra-starter-kits)
- [What starter kits leave out](https://finandfilter.com/starter-kits/what-starter-kits-leave-out)
- [How to set up a 10 gallon fish tank](https://finandfilter.com/starter-kits/how-to-set-up-a-10-gallon-tank)
- [What size tank should a first aquarium be?](https://finandfilter.com/starter-kits/what-size-tank-for-a-first-aquarium)

### Filters & Filtration

- [The best aquarium filters for a beginner tank](https://finandfilter.com/filters/best-aquarium-filters)
- [The best filter for a 10 gallon tank](https://finandfilter.com/filters/best-filter-for-a-10-gallon-tank)
- [The best filter for a 20 gallon tank](https://finandfilter.com/filters/best-filter-for-a-20-gallon-tank)
- [The best filter for a betta tank](https://finandfilter.com/filters/best-filter-for-a-betta)
- [Sponge filter vs hang-on-back: which one for your tank](https://finandfilter.com/filters/sponge-filter-vs-hang-on-back)
- [AquaClear 20 vs Aqueon QuietFlow 10](https://finandfilter.com/filters/aquaclear-vs-aqueon-quietflow)
- [How to size an aquarium filter](https://finandfilter.com/filters/how-to-size-an-aquarium-filter)
- [Do I need a filter for a betta?](https://finandfilter.com/filters/do-i-need-a-filter-for-a-betta)
- [Where to place your filter and heater](https://finandfilter.com/filters/where-to-place-a-filter-and-heater)

### Cycling & Testing

- [How to cycle a fish tank](https://finandfilter.com/cycling/how-to-cycle-a-fish-tank)
- [The best aquarium test kits](https://finandfilter.com/cycling/best-aquarium-test-kits)
- [Test strips vs liquid test kits](https://finandfilter.com/cycling/test-strips-vs-liquid-test-kits)
- [Do bottled bacteria starters work?](https://finandfilter.com/cycling/do-bacteria-starters-work)
- [The fishless cycle, step by step](https://finandfilter.com/cycling/fishless-cycle-step-by-step)
- [New tank syndrome: what it is and how to fix it](https://finandfilter.com/cycling/new-tank-syndrome)

### Stocking & Fish

- [The hardiest fish for a first aquarium](https://finandfilter.com/stocking/hardiest-fish-for-beginners)
- [Easy live plants for a beginner tank](https://finandfilter.com/stocking/easy-live-plants-for-beginners)
- [How many fish in a 10 gallon tank?](https://finandfilter.com/stocking/how-many-fish-in-a-10-gallon-tank)
- [How to add fish to a new tank](https://finandfilter.com/stocking/adding-fish-to-a-new-tank)
- [Can a betta live with other fish?](https://finandfilter.com/stocking/can-a-betta-live-with-other-fish)
- [What size tank do goldfish need?](https://finandfilter.com/stocking/what-size-tank-do-goldfish-need)
- [Do goldfish need a filter and a heater?](https://finandfilter.com/stocking/do-goldfish-need-a-filter-and-heater)

### Water Care & Maintenance

- [The best aquarium water conditioners](https://finandfilter.com/water-care/best-aquarium-water-conditioners)
- [The best aquarium gravel vacuums](https://finandfilter.com/water-care/best-gravel-vacuums)
- [Seachem Prime vs Stability](https://finandfilter.com/water-care/seachem-prime-vs-stability)
- [Python water changer vs bucket and siphon](https://finandfilter.com/water-care/python-water-changer-vs-bucket)
- [How often to change aquarium water](https://finandfilter.com/water-care/how-often-to-change-aquarium-water)
- [How to lower ammonia in a fish tank fast](https://finandfilter.com/water-care/how-to-lower-ammonia-fast)
- [Why do my fish keep dying?](https://finandfilter.com/water-care/why-do-my-fish-keep-dying)
- [Why is my fish tank water cloudy?](https://finandfilter.com/water-care/why-is-my-fish-tank-water-cloudy)

## About and policies

- [About Fin & Filter](https://finandfilter.com/about): who writes this and what it does and does not claim.
- [Editorial policy](https://finandfilter.com/editorial-policy): sourcing standards and corrections.
- [Affiliate disclosure](https://finandfilter.com/affiliate-disclosure): how the site is funded.
- [Privacy policy](https://finandfilter.com/privacy-policy)
- [Terms of service](https://finandfilter.com/terms-of-service)
- [Contact](https://finandfilter.com/contact) — info@finandfilter.com
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