Buying Guides

The aquarium industry is built on the assumption that you, the buyer, do not know what you need. Pet shops sell starter kits that are missing half the equipment required to keep fish alive; online retailers list products with inflated flow ratings and fake wattages; “complete” nano tank packages ship without heaters because the marketing photo looks cleaner without one. The buying guides in this section exist to push back against that — to tell you what is worth spending money on, what is not, and which “essential” products are optional or actively harmful.

Three rules frame every guide in this section. First, buy the tank and the filter before you buy anything else — these are the two pieces of equipment you cannot cheap out on, and everything else is downstream of the choices you make here. Second, do not buy fish on the same trip as the tank — the tank has to cycle for weeks before it can safely hold fish, and impulse fish are the single most common way new aquarists kill their first livestock. Third, avoid the “complete kit” trap: most starter kits include a filter too small for the tank, a heater underpowered for the volume, and a light that grows algae but not plants. The Research Before You Buy guide covers the broader principle; the specific guides below cover the individual product categories.

The Choosing the Right Tank Size guide is the place to start. The size of your tank decides which fish you can keep, which filter you need, how much substrate to buy, and how much maintenance you will be doing for the next decade. New aquarists consistently underestimate the cost of small tanks (more maintenance, more crashes, more equipment-per-gallon) and overestimate the cost of larger tanks (water is free; the marginal cost of a 20-gallon over a 10-gallon is small). Pair the tank size guide with the Tank Size Calculator to convert tank dimensions to true water volume before you commit.

On a tight budget, the nano tank budget guide walks through what a complete 10-gallon setup actually costs, line by line, with the three things you can cheap out on and the three things you absolutely cannot. The equipment recommendations guide lists specific products by category — not affiliate puffery, but the items we have actually used long enough to recommend or warn against. The nano tank equipment guide covers the framework: what each piece of equipment does, what specs matter, and what marketing language to ignore.

Fish buying deserves its own discipline. The best fish for beginners guide lists species that forgive the early mistakes you will inevitably make — hardy, adaptable, and tolerant of the parameter swings that happen in the first months. The companion principle — research every species before you buy, never trust the shop label — is covered in Research Before You Buy. Together these two guides will save you more money (and more fish) than any equipment guide on this page.

The minimum viable equipment list

For a freshwater tropical community tank, the floor is: a tank (obviously), a filter rated for at least 1.5× your water volume, a heater sized to your tank (5 watts per gallon as a rough rule), a thermometer (the stick-on strip ones are inaccurate; spend $8 on a glass or digital), a liquid test kit (API Freshwater Master, not strips), a dechlorinator (Seachem Prime or equivalent), a gravel vacuum, a bucket you dedicate to the tank, and fish food. That is the floor. Everything else — lights beyond the kit LED, CO2, fertilisers, multiple filters, UV sterilisers, automatic feeders — is upgrade, not requirement. New aquarists consistently buy upgrades before they own the floor, then wonder why their fish keep dying.

A note on affiliate disclosure: the buying guides on this site include affiliate links where we have a relationship with a retailer. The affiliate disclosure page is linked in the footer of every page. The principle we hold to is simple: we only link to products we would recommend regardless of whether we earned a commission, and we explicitly call out products we do not recommend even when an affiliate program exists for them. If a guide reads like a sales pitch, it is wrong — please tell us.

More buyer’s guides are in progress. The coming-soon cards below show what is being written: best aquarium kits (and which to avoid), best aquarium heater sizes (with the wattage math), choosing aquarium substrate (gravel vs sand vs aquasoil vs soil), choosing aquarium filters (HOB vs canister vs sponge by tank size), and choosing aquarium lighting (PAR, not watts). Until those land, the equipment category page and the existing equipment guides cover most of what you need to make a buying decision.

One final note on second-hand equipment. Used tanks are the single best value in the hobby — a 55-gallon tank that retails for $200 can be had for $40 on local classifieds, often bundled with a stand, filter, and heater. The risks are few and the savings are large: check the silicone seams for separation or mould, fill the tank in a garage or yard before bringing it inside, and replace any filter that has been sitting dry for more than a year (the impeller seals fail). The trade-off is time — you wait for the right listing instead of buying what is in stock. For anyone whose budget is the constraint, second-hand is the path to a larger, more stable tank than the new small tank you could afford at retail.