Most aquarium maintenance advice is written for an imaginary keeper with one tank and unlimited enthusiasm. Real life is different: some weeks you have twenty minutes for the fish, some weeks you have two, and any schedule that demands perfection will be abandoned by March. Running several tanks plus outdoor tubs has forced me to figure out what actually needs doing, what can slide, and what should never be done at all. The short version: a tank needs a small amount of genuinely regular work, mostly water changes, and it is harmed by heroic irregular work. Here is the schedule that survives contact with a normal life.

Daily: two minutes, mostly looking

Daily maintenance is observation, not labour, and it happens naturally at feeding time.

  • Feed, and watch everyone eat. The feed is the health check. A fish that hangs back, breathes hard, or sits clamped in a corner is telling you something days before it shows spots or wounds. Count heads in tanks where that is feasible. Sensible portions are covered in feeding aquarium fish; the maintenance-relevant point is that overfeeding is the single biggest generator of maintenance work, because everything you put in ends up as ammonia, nitrate or mulm.
  • Glance at the kit. Filter outflow moving, heater light behaving, temperature roughly right. A failed heater or a stalled filter found on day one is a non-event; found on day four it is a disaster.

That is the whole daily list. Anyone telling you a tank needs daily testing or daily gravel cleaning is describing a tank with a problem, not a routine.

Weekly: the water change is the hobby

One job carries the entire hobby: the partial water change. Weekly, 25 to 50 percent depending on stocking, with a gravel vacuum over the open areas of substrate while the water drains. Everything else on this page is negotiable; this is not. Nitrate and other dissolved waste only leave the tank in a bucket, and the full reasoning is in aquarium water changes. If you are unsure what percentage your tank actually needs for its stocking level, the water change calculator will give you a number to start from, and lightly stocked tanks genuinely can run on less.

The trick to doing it every week for years is reducing friction. Keep the bucket, siphon and dechlorinator together in one place. Do it on the same day each week, tied to something you already do. My changes are unglamorous and quick: drain with a gravel vac, refill with temperature-matched dechlorinated tap water, done. Twenty minutes for a medium tank, less once practised.

While the water is draining, the other weekly jobs happen in the same session:

  • Wipe the front glass with a clean sponge or algae magnet, before the water change so the debris gets siphoned out. Leave the back glass for the algae grazers; it does not need to be sterile.
  • Prune and tidy plants, netting out floating dead leaves. Rotting leaves are fertiliser for the algae you just wiped off. Ten minutes here saves an afternoon later, and low-effort species from the beginner plants list barely need this.
  • Top up evaporation in open tanks, remembering that evaporation concentrates minerals; in hard-water areas like mine, topping up repeatedly without water changes ratchets the hardness upward.

Testing is weekly only for new tanks. During cycling and the first couple of months, test ammonia, nitrite and nitrate weekly; the meaning of each number is in aquarium water parameters. A mature, stable tank needs testing when something looks wrong, before adding livestock, and occasionally out of curiosity, not on a calendar.

Monthly: filters, done the right way

Once a month or so, some jobs come due that do not fit the weekly slot.

  • Rinse the filter media, in tank water only. This is the most important sentence in the article. Your filter media hosts the bacterial colony that keeps the tank safe, and tap water’s chlorine is specifically added to kill bacteria. Squeeze sponges and swirl ceramic media in a bucket of the water you just drained during a water change, until the worst of the sludge clouds out, then put it all back. Brown and dirty-looking is fine; biological media never needs to be clean, it needs to be unclogged. The layout and purpose of each media type is covered in aquarium filtration, and if your filter needs this more than monthly, the filter is undersized for the tank, which is a filter choice problem rather than a cleaning problem.
  • Replace nothing on a schedule. Cartridge systems are designed to sell you cartridges. Sponges last years; replace media only when it is physically falling apart, and then only part of it at a time so the bacteria carry over.
  • Check the hardware. Pull the impeller out of the filter and rinse the slime off it, check heater and thermometer agree with each other, clean the lid or cover glass so light reaches the plants, and top up or clean airline non-return valves if you run air.
  • Deeper gravel vac in a different zone each month. Rather than deep-cleaning the whole substrate at once, I do the open foreground weekly and rotate a deeper clean around the tank month by month, leaving planted areas largely alone.

What not to do: the deep-clean disaster

The most dangerous maintenance in the hobby is the big spring clean, and it usually follows a guilty conscience. The tank has been neglected, so one Saturday everything happens at once: full gravel wash, filter media scrubbed under the hot tap, ornaments bleached, 90 percent water change. The tank sparkles, and within a week the fish are gasping, because the keeper has done to their tank what took weeks of fishless cycling to build, in reverse, in an afternoon. The bacteria lived in that filter sludge and gravel bed, the tank is now effectively uncycled with a full fish load, and the ammonia spike arrives on schedule. The same panicked cleaning is a classic cause of the milky bacterial blooms covered in cloudy aquarium water.

The rules that prevent it are simple. Never clean the filter and do a heavy gravel vac in the same week. Never rinse biological media in tap water. Never change close to all the water in one go unless you are responding to a genuine poisoning event. A neglected tank is recovered gently, with normal-sized water changes every day or two over a couple of weeks, not with one heroic purge.

Make the schedule fit the keeper

A schedule you follow at 80 percent beats a perfect one you abandon, so design for your own laziness. Understock rather than overstock, since a lightly stocked tank forgives a skipped week and an overstocked one punishes it. Prefer fewer, larger tanks over many small ones if time is short; a big tank drifts slowly. Keep the tools where the tank is. And write the filter-rinse date on a bit of tape on the cabinet, because nobody remembers when they last did it. The whole hobby, reduced to honest arithmetic, is this: feed lightly, look at your fish every day, change some water every week, rinse the sponge in the bucket once a month, and refuse all invitations to do anything dramatic.