01 / Roundup
The best betta food
Betta food judged on protein source and granule size, plus the honest note that guaranteed test results are rarely published on the product page.
Care
Care, on a schedule you can actually keep
A cycled 5-gallon needs about fifteen minutes a week. Getting there takes a month you cannot skip, and that month is where most betta tanks are lost.
Orientation
Betta care is not hard. It is front-loaded. Almost all of the work, and all of the risk, sits in the first month - before the fish arrives, if you do it properly - and after that a small planted tank asks for about fifteen minutes a week for years.
The thing that makes the first month non-negotiable is the nitrogen cycle. Fish produce ammonia. Ammonia is lethal. Two families of bacteria convert it, first to nitrite (also lethal) and then to nitrate (largely harmless at the levels a betta tank reaches). Those bacteria have to colonize your filter before there is a fish in the tank, and they take three to six weeks to do it. There is no product that removes that wait, including the bottled bacteria we recommend - it shortens the wait, it does not delete it.
What to buy, if you read nothing else
A dechlorinator and a liquid test kit. Those two purchases, together under forty dollars, are the difference between keeping a fish and watching one die of something invisible.
Seachem publishes Prime at 5 mL per 50 US gallons of new water, which works out at a fifth of a milliliter for a typical 5-gallon water change - buy a 1 mL syringe, not the cap, because a capful in a nano tank is a ten-times overdose. For testing, buy liquid reagents rather than strips. Strips answer “is it roughly fine”; during a cycle you need to know the difference between 0 and 0.25 ppm of ammonia, and strips cannot tell you.
The weekly routine, in full
A 25 to 50% water change, temperature-matched, dechlorinated. A quick siphon through the open substrate - not a deep dig, which just releases everything you were trying to remove. A wipe of the front glass. That is it. Fifteen minutes.
You do not rinse the filter media on this schedule. Media gets rinsed in old tank water, in a bucket, when flow visibly drops - maybe every two or three months. Rinsing filter media under the tap kills the bacteria with chlorine and re-cycles the tank, which is a genuinely common way to lose a fish in month three.
Feeding, which is where the second half of the deaths come from
A betta’s stomach is roughly the size of its eye. Feed two or three granules once a day, or a slightly larger meal five days a week. Everything uneaten becomes ammonia in a very small volume of water.
A betta is an insectivore. That is not a marketing angle, it is the reason an insect-based food beats a fish-meal-and-wheat pellet for this species specifically. Whatever you buy, check the granule size - a food the fish physically cannot get in its mouth is just ammonia on a delay.
The mistake keepers make
Reacting to a number instead of a trend. New keepers test daily, see nitrate at 20 ppm, and do a huge water change. Nitrate at 20 is fine. What matters is whether it is climbing week on week, and whether ammonia and nitrite are at zero. Write the numbers down. A tank you have four weeks of readings for tells you what is happening; a tank you tested once tells you nothing.
If you buy one thing
Seachem Prime
Seachem publishes 5 mL per 50 US gallons, so a 5-gallon water change is a fraction of a milliliter and a 100 mL bottle is hundreds of changes. It also binds ammonia and nitrite, which is what turns a cycling accident into a survivable week.
Skip it if: You need something you can dose by the capful into a nano. At this concentration a capful in a 5-gallon is a ten-times overdose - you are measuring in drops.
What decides this
How long should a betta live?
Three to five years from hatching is the range generally published, and pet shop fish are typically six months to a year old when you buy them. So two to four years in your tank is a realistic expectation, and a betta that dies at eight months almost always died of temperature, ammonia, or both - not of old age. We go through this properly on the lifespan page, including what the number is actually based on and why the commonly quoted figures vary so much.
What we will not tell you
What is wrong with your sick fish. Diagnosis from a description is unreliable, the difference between fin rot and fin damage is not something a website can establish from a photograph, and we hold no qualification that would make the attempt responsible. Where a symptom has a clear environmental cause - and with bettas it very often does - we say so. Where it needs a diagnosis, we say that instead of selling you a bottle.
What we do cover is the treatments themselves, under stricter rules than anything else here: only what the manufacturer prints, absences recorded as absences, and the free step ranked above the purchased one. What each symptom means sorts what you can see, and fin rot and swim bladder problems have a page each. Most aquarium medications are still sold with no dosing data for a 4-gallon volume, and those pages print that rather than working around it.
We still do not run a “best betta medication” roundup. The pages are organized by condition rather than by product, and where a maker publishes no evidence for a popular remedy we rank it last and say why.
The picks
02 / Roundup
The nano tank maintenance kit
The gravel vacuum actually rated for a nano, the dechlorinator dose worked for a 5-gallon water change, the algae magnet, and the one item nobody publishes a product page for.
Aqueon Siphon Vacuum Gravel Cleaner, Mini 5"
Our best nano maintenance kit pick on this page.
03 / Roundup
The best aquarium water test kit
Why liquid reagents beat strips for the one test that matters, what each kit publishes, and the honest reason a nano keeper needs testing more than a big-tank owner does.
04 / Roundup
The best automatic fish feeder
Automatic feeders judged on portion control at nano scale and on moisture caking, with the honest case for skipping one on a short trip.
Fish Mate F14 Aquarium Fish Feeder
Our best automatic fish feeder pick on this page.
When two options both look right
05 / Comparison
Pellets versus flakes versus frozen
The four food formats compared on portion control, water fouling and suitability for a small upturned mouth, plus the freeze-dried mistake that causes bloating.
06 / Comparison
Seachem Prime versus Stability
Prime treats the water you add; Stability seeds the bacteria that process waste. The published doses for each, converted to nano volumes, and which to buy first.
Work it out first
07 / Guide
Betta fish care
The complete practical guide: tank, temperature, filtration, feeding, water changes and the weekly routine, with every figure computed from published data.
08 / Guide
How to cycle a betta tank
The fishless cycle step by step, with published bacteria dosing converted to nano volumes, the readings to expect each week, and how to cycle with a fish already in the tank.
09 / Guide
Betta tank cleaning schedule
What to do weekly, monthly and never, with the dechlorinator dose computed per tank size and the common routines that quietly re-cycle a tank.
10 / Guide
How long do betta fish live?
The lifespan figure, why the fish you buy has already used part of it, and the four environmental factors that account for most premature betta deaths.
11 / Guide
Do betta fish need light?
What an aquarium light is really for in a betta tank, the photoperiod we run and why it is our judgment rather than a published figure, and the sunlight mistake.
12 / Guide
Seachem Prime review
What Prime actually does, the published dose worked for a nano water change, the overdose tolerance Seachem states, and the one thing it is routinely misused for.
13 / Guide
How to lower nitrates in a nano tank
The dilution arithmetic for a nano water change, why slow plants barely move the number, the feeding input people miss, and the three products the job actually needs.
14 / Guide
Cloudy aquarium water, by color
White, green, brown and gray cloudiness have different causes and different fixes. The diagnostic, why a clarifier is usually the wrong purchase, and what to test.
15 / Guide
Betta at the top of the tank
Why surfacing is normal for a labyrinth fish, the four measurable causes that make it a symptom, and the order to check them in.
16 / Guide
How often to feed a betta, and how much
The feeding schedule we run, why the portion matters more than the frequency, and what the food makers do and do not publish about quantity.
17 / Guide
How to lower pH in an aquarium
Why we do not recommend chemical pH adjusters, what tannins and active substrate really change, and how to tell whether you have a problem at all.
18 / Guide
Sick betta symptoms, by what you can see
A symptom-by-symptom table, what each one narrows the cause down to, and the short, honest list of what to keep in the cabinet before you need it.
19 / Guide
Betta fin rot, and what actually treats it
Why clean water is the treatment rather than the preparation, the published salt dose for a 5-gallon, and the one medication that names fin rot on its label.
20 / Guide
Betta swim bladder, bloating and buoyancy
Why buoyancy failure in a betta is usually a feeding result, the fast that treats it, and an honest reading of what Hikari actually claims about daphnia.
The next decision this one leads to
A nano tank is one system, not six purchases. Volume sets the wattage, the wattage sets the heater, the heater and the filter between them set what you can stock, and the plants decide whether any of it stays stable.