Looking after one betta takes about a minute a day and ten minutes a week. The harder part is knowing what to leave alone, because most of the damage keepers do to healthy tanks is done with good intentions and a scrubbing brush.
Every day
Look at the fish. Thirty seconds. Are the fins carried open or folded tight against the body? Does it come to the front of the tank? Is it breathing at a normal rate? Any spots, patches or ragged edges that were not there yesterday?
This is the single most valuable habit in fishkeeping. You are building a baseline, and the value is that you notice a change on day one rather than day ten.
Read the thermometer. Not the heater dial, which is often wrong. You are checking that nothing has drifted and that the heater has not failed, in either direction.
Feed. Two to four small pellets, once or twice a day, finished within about two minutes. Remove anything still floating after that.
Every week
Ten minutes, and it goes faster if the siphon, bucket and test kit live together in one place.
- Test ammonia, nitrite and nitrate. Same day and roughly the same time each week so the readings are comparable.
- Vacuum the substrate lightly while siphoning out about 25 percent of the water.
- Wipe the inside of the front glass. Leave the back and sides if you like; algae there is harmless and grazed on.
- Refill with dechlorinated water matched to tank temperature.
- Check the equipment. Filter still flowing, heater indicator behaving, lid properly seated.
- Top up plants if any are floating loose.
Twenty five percent is the number for one betta in five to ten gallons. Larger changes are for problems, not for routine.
Every month
Rinse the filter media in removed tank water. Squeeze the sponge out in the bucket you just siphoned into, then put it back. That is the whole job.
Never rinse it under the tap. Chlorine kills the bacterial colony that keeps ammonia at zero, and a tank whose filter was rinsed in tap water is an uncycled tank the following day. This is one of the most common causes of an established tank suddenly showing ammonia.
Do not replace media that is merely dirty. Dark, slightly slimy media is mature media. Replace it only when it is physically disintegrating, and then keep the old piece in the tank alongside the new one for a few weeks.
Also monthly: check the heater and thermometer against each other, and look at the lid and its cable gaps.
Occasionally
Trim plants when they shade everything below them. Replace the thermometer if it looks doubtful. Deep clean the glass exterior. Check the date on your test kit reagents, which do expire and quietly start giving wrong answers.
What not to do
| Tempting | Why not |
|---|---|
| Full water change | Removes the bacterial colony and shocks the fish |
| Scrubbing every surface | Biofilm and darkened media are where bacteria live |
| Rinsing media under the tap | Kills the cycle outright |
| Replacing filter cartridges monthly | Throws away the colony. This is why cartridge filters sell cartridges |
| Rearranging the decor often | A betta maps its territory. Constant change is a stressor |
| Daily water testing on a stable tank | Not harmful, just unnecessary once you know the tank |
Fishkeeping rewards restraint more than effort. A tank left alone with a weekly quarter change is more stable than one that gets enthusiastically maintained.
If you miss a week
Test, do the change, carry on. One missed week on an established tank with a single fish is usually a slightly worse nitrate reading rather than an emergency, and it is more forgiving in ten gallons than in five.
Do not double the size of the next change to catch up. A large sudden change swings the chemistry, which is harder on the fish than the nitrate was.
Where to go next
The care guide is the hub for everything above. The water change article covers technique in detail, and the testing walkthrough covers getting readings you can actually trust.