Aquarium Cleaning & Maintenance Guide
by Pearl A.
Let's hope your tank never looks like this one!
Maintaining a clean aquarium is really not so bad; but it can be frustrating to figure out exactly how to go about it.
We've broken it down into a daily, weekly, monthly and semiannual checklist you can use as a general guide to keeping your aquarium in top shape.
There are plenty of "right ways" to clean your aquarium, and everyone develops their own method. Use your common sense - if things are getting dirtier before you're scheduled to clean, then clean more frequently - or determine if you need a more powerful filter or better circulation! Maintenance is rewarding in its own right - the fruits of your labor will shine through loud and clear.
Observe your tank closely at least once a day. While you're enjoying the view, take note of a few things.
- The temperature on your thermometer should match the temperature on your heater's thermostat. If you see a temperature readout you aren't expecting, get a new heater immediately. (It's a good idea to use 2 instead of one anyway - heats more evenly and provides cheap insurance.)
- Mark the fill level on the glass on the back of your tank or some other discreet area, and then check your water level if it starts to look low.
- Top off evaporated water when the level starts to drop. Dissolved solids like salts do not evaporate, so evaporated water can cause spikes in salinity or pH because the solution in your tank becomes more concentrated. Prepare top-off water as you would for a water change, but without adding salt or mineral supplements.
Dead Fish or Organisms
- New fish may take a while to settle into normal behavior. Recent changes such as a new addition to the tank can cause shifts in normal behavior. But most of the time, fish are pretty consistent.
- Be alert to signs of strange behavior, like a loss of appetite, unusual swimming patterns, or rubbing against ornaments. Signs of illness, such as white fuzz, erratic swimming, or rubbing against ornaments should be dealt with immediately - ideally by moving suspect fish to a quarantine tank and medicating it there.
- Small fish that like to hide in decorations or rock crevices could easily die and be unnoticed for days. Anemones and plants are also notorious for dying discreetly.
- A dead organism immediately begins to decompose and will soon flood your system with toxic ammonia, likely more than your filters are prepared to handle - especially in smaller tanks. So do a head count every day and remove anything that will decay.
- A protein skimmer's collection cup should be emptied of skimmate every few days or so - whenever it is full. Your skimmer will take a few days to get up to speed; once it's functioning smoothly, check the cup daily; after a few days you'll be able to determine how often you need to clean it.
The regular water change is the most important thing you must keep up with for the health and appearance of your aquarium. Normally, a water change is only partial - you remove 15-25% of your tank water and replace it with completely new water. Changing more than 30% or so of water at a time can be stressful to fish and is usually avoided unless removing medication or fighting some sort of water quality problem.
Changing water is important because for the vast majority of aquarium systems, there is no other way to remove nitrates from water. Every day, bacteria convert fish waste and excess food into nitrates, so levels are constantly climbing; plants or algae may consume some, but not usually enough to hold nitrate at steady levels. Nitrate is not tolerated well by marine organisms; it's tolerated a little better by freshwater creatures. But in any tank, you must control nitrate levels by frequently removing nitrate-laden water.
Typically, water changes are performed once a week. But small tanks up to about 10 gallons, where the small volume of water means changes in condition have more impact, usually benefit from 2-3 water changes per week. The same is true for "nano" saltwater tanks (20-40 gallons or less) which need very stable conditions. Large tanks, by contrast, might be fine with a water change every 2 weeks. It depends on your bioload, or the amount of waste produced by your aquarium organisms.
You can tell if you're changing water enough by measuring nitrates weekly, a day or so after a water change. If your nitrate levels decrease or remain the same from week to week, you are changing frequently enough. If they climb, you need to change more frequently. Since this is directly related to how much waste your creatures are producing, levels that stay dangerously high or persist in climbing may mean you're overstocked.
A freshwater tank's nitrates should stay safely below 40ppm; a saltwater tank should be around 10-20ppm, the lower the better, especially for sensitive reef tanks.
Water changes are the best time to do some easy cleaning chores. More tips on water changing to follow:
During a weekly or biweekly cleaning routine, you are concerned with two things: cleaning algae and debris from your tank and gravel, and doing your partial water change.
Water Change/Cleaning Routine
- First, prepare replacement water for your tank. Add any conditioner or dechlorinator that you use and let it sit and adjust to room temperature. If using RO filtered water, like many saltwater hobbyists, it's a good idea to aerate the water first with a powerhead on the mixing bucket - filtered water has very little oxygen and could cause a shock to your system.
- Siphon off 10-25% of your water. Using a bucket or a water changer that feeds into a sink are the usual methods. Don't discard water immediately if you intend to rinse mechanical filter media of debris, or rinse ornaments.
- Leave your fish in the aquarium - moving them is more stressful than a water change. But take care that your movements in the tank are slow and gentle - try not to disturb the water too much when removing or adding.
- Use an algae scraper or scrubber to remove any dirt or algae that's accumulated on your tank walls. They're made either for acrylic or glass, so use the right one to avoid scratching your tank.
- Rinse any debris off decorations in the water you removed from your tank. If rinsing any filter media, use discard water for that too (see next section for more about filter media).
- If you have live plants, it's a great time to prune, re-anchor, and remove any dead bits.
- Using a gravel vacuum or siphon, suck particles of debris ("mulm") from your gravel and anything floating in your water. Stir the gravel or sand lightly with your siphon as you go.
- Once clean, slowly siphon your new water back into your tank. Siphoning slowly rather than pouring will help the water temperature adjust gradually, avoiding shock to your fish. It'll also keep water disturbance to a minimum, which avoids further trauma and keeps your water from getting too clouded during the process.
- After cleaning, you may find clouding, condensation or bubbles in the water. These are usually just due to the disturbance of cleaning and should go away within a couple of days.
- If you're regularly finding lots of debris when you vacuum your tank, it could indicate your tank is overstocked or you are overfeeding. You may need a more powerful filter or to clean more often.
It's a great idea to record monthly maintenance tasks in a log or journal when you do them, so you can easily tell when you need to do them next; also to follow developing trends, identify possible problems and keep up on refill changes.
Refill or Clean Media
- Unless you're in a period of transition - new fish, recently dead or ill fish, etc - you can probably get away with testing pH levels, ammonia, nitrites and nitrates monthly - but keep records of the results, days and times that you took them. (pH varies throughout the day, so measuring at the same time matters.)
- If water conditions ever seem suspicious or there is a mystery problem in your tank, measure these levels and check for changes. You can then refer to these measurements if you ever need to consult other hobbyists or experts about your problem. They will go a long way towards figuring out what is wrong.
- Most filter cartridges and chemical filter media need to be replaced roughly once a month (follow directions).
- Biological media should only be rinsed if it is clogged with debris, but never rinse a significant portion at once; do it in rotating batches and let a week or more go by before you do the next. A light film of slime shouldn't be cause for concern. Biological media normally doesn't need to be replaced, and shouldn't be.
- Make sure you power off and unplug any equipment you are working on.
- Rinse pads and sponges in aquarium water - do this during a water change, so you can use the water you removed from the tank. If they are so clogged they can't be cleaned, it's time to replace them. Do this every two weeks instead if they're growing dirty quickly.
- When you clean your media, observe the inside of your filter components - if there is a lot of gunk clogging up the works, remove it with a flexible cleaning brush.
- Throughout the month you'll notice - hopefully - if your air stone notably slows in bubble production. Whenever you observe a big drop in bubbles, the stone needs to be cleaned or replaced.
- Air stones of all types can usually be cleaned well by boiling in clean water, then soaking in vinegar for about a day. Once calcium or other deposits are gone, attach an airline from your air pump and running the stone in fresh water for 5-10 minutes. Remove stone from water while running the pump a few minutes longer. Let air dry.
Don't hesitate to do these tasks more frequently if equipment is getting dirty/clogged before six months is up. This is how you preserve the life of your equipment and keep everything functioning smoothly - so don't be shy about it!
Record biannual maintenance in your maintenance log so you can keep track of when you need to do it.
Light Bulbs/ UV Bulbs
Pumps, Filters & Protein Skimmers
- Unless stated otherwise by the manufacturer, light bulbs and UV lamps usually need to be replaced every six months. Even if you see light, wavelengths of the original spectrum gradually decay, so your aquarium isn't getting "daylight" anymore.
- Changing bulbs at night is easier - it allows lamps to cool before you have to handle them, and you won't have to disrupt your tank's normal photoperiod.
- For light intensive systems that use multiple lamps, change out lamps one at a time over a period of days - the sudden heightened intensity can be a shock to organisms.
- Never touch a metal halide lamp with your fingers even when cool; use a glove. The oils from your fingers weaken the glass and with such intense heating, could cause an explosion.
- If you're starting out, you may want to check pumps and filters every three months at first - depending on your bioload, they may need cleaning more often than twice a year. But for many systems, it should be adequate.
- Pumps and filters house a motor and impeller. To clean them, remove the impeller (pictured right) following manufacturer's instructions and clean debris from it and its housing. If the impeller is missing blades or is cracked, replace it.
- Clean all housings, intake and outlet pipes and the body of the filter or pump. You may need a filter or tubing brush to get all the way inside these parts, but don't skimp out on this cleaning - after all, it has to get you through the next half of the year.
- Lubricate moving parts that need to be (follow instructions). Some pumps need regular oiling with a special oil.
- Reassemble and reinstall. Some filters and pumps need to be primed before they will start.
- While you're in the cleaning mindset, take a look at any equipment we haven't mentioned, and clean its housing or take it apart for thorough cleaning if appropriate.
Finally, remember to enjoy your tank! Some hobbyists give up because they begin to see their aquarium as a chore and not a reward. We think the chore has its own rewards, but it's important to take the time to experience your aquarium passively - as an admiring observer - and remember why you were drawn by this hobby in the first place. Your efforts have created a livable, healthy habitat for some of the earth's most amazing creatures, not to mention a work of beauty - and for that you should be proud!
We encourage readers who find this information beneficial to share it with friends or other interested parties. Link to this article from your own websites!