Aquarium Maintenance Tips and Fish Care Guidelines

Neon tetras in clear water freshwater aquarium

Topic Overview

Learn about the essentials of aquarium maintenance. Maintenance should include water changes, servicing the filter & testing the aquarium water.

Spending about thirty minutes on aquarium maintenance every other week, helps prevent common and time consuming problems.

The main goal of routine maintenance is a stable and balanced aquarium.

If everything is running properly and your fish are healthy, there is no need for any major change, even if the pH or hardness is slightly out of range. Only increases or decreases of any major water parameter will require careful but immediate attention.

Aquarium Water Changes

Water changes are arguably the most important part of routine aquarium maintenance

Scheduled aquarium maintenance would not be complete without the water change. We recommend an average water change of 10 – 15%, every two weeks.

Aquarium water change siphon

Maximize your efforts by using a siphon to extract aquarium water while “vacuuming” the gravel. This will remove uneaten fish food, fish excrement, and other harmful waste settled at the bottom of the aquarium.

When performing aquarium maintenance, test the water parameters of both, the aquarium and replacement water.

Tap water (municipal water) contains chlorine or chloramine. Chlorine will air out if kept in an aerated bucket for twenty-four hours. Chloramine will not. Chloramine = chlorine + ammonia.

Either way, it is best to use a water conditioner to neutralize the chlorine. We should note that ammonia will remain in the water if it contained chloramine, even after treatment with a conditioner. Nitrifying bacteria will break down the ammonia after adding the water to the aquarium.

Other elements of municipal water may be phosphates, iron, and other heavy metals. Contact your water company if you aren’t sure it’s safe for use in your aquarium.

Generally, well water is harder than municipal water, but it should be chlorine and chloramine free.

If you are using filtered water, it’s still a good habit to regularly check it for vital parameters. Replace the filter membranes according to the manufacturer’s recommendations.

Testing the Aquarium Water

Regular aquarium maintenance would not be complete without testing important water parameters

Because we can’t determine water quality by looking at it, it is very important to do regular testing. Testing your aquarium water is like checking the body’s vital signs. The results can tell us a lot about imbalances, therefore allowing us to detect and prevent looming problems.

Aquarium water test kit

Vital parameters to test as part of routine aquarium maintenance include nitrate, nitrite, pH, carbonate hardness, and salinity (saltwater only)

We highly recommend including testing in your regular maintenance schedule. Below are our basic guidelines for testing important aquarium water parameters.


Nitrates should be kept below 10 ppm in freshwater, and 5 ppm or lower in saltwater and reef aquariums.


Nitrites should be undetectable at all times (except during cycling). If nitrite is detectable, be sure to test for ammonia as well.


pH must remain stable. pH in the range of 6.5 – 7.5 is suitable for most species, but they should be fine if it’s slightly out of range.

KH (carbonate hardness)

KH (carbonate hardness) is a measure of pH stability. If KH drops close to 4.5 dH (degree hardness) or 80 ppm, you should monitor it frequently. If hardness drops below 45 dH, the pH of the aquarium water will crash.

A half teaspoon of baking soda per twenty-five gallons of water, raises kH by approximately 1 dH (17.8 ppm).

Filter Maintenance

Regular aquarium maintenance includes servicing the filter

The aquarium filter should be serviced monthly. A densely stocked aquarium may require more frequent filter cleanings.

Hang on back aquarium power filter

Think of your aquarium’s filter the same way you think of your kitchen trash can. The filter is nothing more than a receptacle for waste. Once it gets “full”, you need to empty it, otherwise it will contaminate the home of your fish.

Servicing and maintaining the filter is simple and straight forward. Change dirty filter inserts, along with any media (activated carbon, Algone, etc.) that is due to be replaced.

Occasionally a complete rinse of the filter is also required. The frequency depends on individual tank conditions, but generally once every 4 weeks is adequate. Avoid touching the bio wheels or any other beneficial bacteria supporting media during this process.

Important: Only use clean, fresh water when rinsing the filter or any other aquarium equipment. Never scrub the inside of the filter. Do not use soap, bleach, or chemical cleaners, because they will kill the beneficial bacteria required for healthy aquarium life.

Recommended Aquarium Maintenance Routine

A complete aquarium maintenance schedule includes daily, weekly, bi-weekly, and monthly tasks


  • Make sure the equipment is running properly.
  • Watch your fish during feeding. Behavioral changes are a good indicator of a potential problem.


  • Count your fish. In case of fish death, smaller species can decompose quickly, resulting in ammonia and nitrite spikes, and eventually high nitrate levels.

Every Other Week

  • Test your water for vital parameters: pH, carbonate hardness, nitrite, and nitrate.
  • Clean the aquarium walls. Filter floss is fairly cheap and very efficient. Start from the bottom upward and rinse filter floss or scrubber frequently.
  • Vacuum the gravel.
  • Change 10-15% of the water.
  • Rinse filter inserts with the extracted water.


  • Replace filter inserts, cartridges, floss, carbon, and Algone. Rinse entire filter if needed.
  • Inspect tubing, connections, airstones, skimmers and other parts for proper operation.
  • Clean aquarium top to assure your lighting is not affected.
  • Check the expiration dates printed on the boxes and bottles of the aquarium supplies you use. Do not use after the imprinted date. Expired test kits will give false readings and may prompt you to take unnecessary action.

In Conclusion

Every aquarium is different and will require a maintenance schedule that is best suited for its unique conditions. Use our aquarium maintenance guidelines outlined in this article as a starting point. From there, you will be able to set your own timelines.

Always remember, it is far more challenging to maintain an overstocked and overfed aquarium, so make sure to avoid both.

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Thomas Jameson

It’s good to know that you should have your aquarium filter serviced on a monthly basis. My wife and I would like to purchase an aquarium to give our home a special aesthetic. We want to make sure that it stays in good condition, so we’ll be sure to get the filter cleaned every month.

Bradford Risbert

Good information. I would however like to add one thing ie. – Observe your fish behaviour. Especially eating habits. Hungry fish are generally healthy fish. If they do not eat food properly, most likely the water is bad.


Tell me the use of malachite green f n its using period, I mean how many times does i have to use it in a month?


I am referring you to this link
This is generally a one time treatment.

Sheryl McCalla

I have a 35-gal aquarium and the issue I have is a bright green algae. I change 15% of the water every 2 weeks but I still have that algae problem. I tested the water and the nitrate level showed 160 or unsafe. I have added a PhosPure Pad with my other filter and it keeps the water crystal clear and treat the water weekly with a Neutral Regulator (Seachem). What can I do to get this nitrate level under control?


Algone will lower and remove your nitrate levels. They are really high and with 160 ppm or higher a definite threat to the health of your fish.


i had 12 Gold fish & 1 moily fish & my fishtank is 2 ft Height, 2 ft width & 1 ft depth. After a week all the fishes died, I don’t know the reason, please help me to maintain properly. How to check Ph level in water. Please reply

Sorry to hear about your fish loss. If you just started your aquarium, please review our articles about the nitrogen cycle aka biological filtration. Every new aquarium must initially “cycle”. This process does not require human intervention. As soon as fish are introduced, waste is created in the aquarium. This waste is broken down by beneficial bacteria. Break down occurs in stages… organic waste > ammonia > nitrite > nitrate. Nitrate is the final result of the breakdown and should be periodically removed through water changes and a nitrate remover such as Algone. During the initial cycling process, ammonia and… Read more »

Ronnie Foley

Just a simple question. Does lighting you use in your tank affect any ph balance in the tank? For instance one of my 10 gallons i use a regular led that came with the aquarium i bought at wal mart. The other light is sumthin that was with rhe tank when i got it. Its not a led.its an ole fashion tank light. Its pretty old. But would that type light affect any of my ph balance? Hope ive asked this question propperly.


Light has no influence on pH

nicasio ruben torres 111

is this available in the Philippines (Algone clarifier)?

We do have asian distributors, but not specifically in the Philippines. Ask your local retailer. If they can’t help, we do have low international shipping rates if you wish to order directly from our website.

Keith Sellers

Yes, I am currently interested in creating another tank into my household. I already have a community schooling tank with tetras and guppies along with a few barbs, a catfish and last but not least a chinese algae eater. Anyhow, i want to move the catfish due to him becoming to large for my 30 gallon tank and i was wondering on tank size, potential tank mate for him, another catfish? Possibly a jack dempsey or an oscar … Please give me a reply, thank you


Oscar or Jack Dempsey will require large tanks 75/ 125 Gallons would be a minimum. Both are not really community fish, it is a cichlid so you could consider other cichlids to complete the setup. Make sure they are larger than snack size.

Santosh J

i have a 15 gallon tank with 12 gold fishes, 2 black widow tetra, 2 silver dollar and 1 angel fish….. total 17 fishes…. i know its crowded…. all fishes about 1 – 1.5 inches in size………. how much percent water change i should do and how many times in a week?? also when should i do complete water change??? currently i do 20-25% water change every 2-3 days with gravel vacuuming and do complete water change in about 1.5 months…. pls suggest

There’s no one-size-fits-all water change schedule. Considering your tank is overstocked, weekly or bi-weekly water changes should be sufficient. At the same time, be sure not to overfeed. Sparingly, once a day is enough. You may even want to skip a day’s feeding on occasion. This will limit the amount of waste entering the tank and help keep a healthy biological balance. If you feed a lot, more frequent water changes will be necessary. A complete change shouldn’t be required at all, as it results in a loss of your beneficial bacteria, requiring the aquarium to start from new. See… Read more »


I want to set up a fresh water cichlid fish tank . I have a 15 gallon tank so suggest me best filter or filtration system for cichlids and how many fishes according to their size should i keep.

Cichlids are territorial fish so I wouldn’t stock more then 3 or 4 in a 15 gallon tank. Having said that, I would recommended a 30 gallon tank minimum to keep cichlids. Provide them with plenty of stacked rocks for hiding places for an ideal environment.

A simple power filter hanging on the back of the tank will do just fine.


when was this article posted month and year, also the publisher? doing homework and using this site..thank you

Originally published about 15 years ago, and updated several times since. Publisher is


I found a 20 gallon tank that sat for too long in a barn disused. I usually fill it with a strong bleach / water solution and let it sit in the sun for a day before setting it up. with this tank I think some extra measures may be prudent. If I use beer brewers sanitizing solution, do you know if there will cause any harm?

You should be ok as long as you rinse the cleaned tank thoroughly with fresh water. Make sure there’s no residual soap or sanitizing solution left before setting up the aquarium.

Robbi Robson

I have a 55 gal tank with 2 biofilters and 2 bubblers. Every day in order to keep my ammonia low I take out 50 to 75% water and replace it with prime for the total volume of the aquarium. Remove all bio in the sand. Every day for 4 months. My api master kit test dark green for ammonia every morning. Haven’t added or lost any fish for 4 months. What am I doing wrong?? Freshwater and I use aquarium salt. Feeding once a day.

You shouldn’t be changing all that water every day. Your aquarium needs to “cycle”. Cycling the tank is the start-up phase of any new aquarium, during which beneficial bacteria (nitrifying bacteria) establish. You need these bacteria. They breakdown organic waste (uneaten fish food, fish poop) in the aquarium. The breakdown of this waste occurs by converting it into ammonia, nitrite, and eventually nitrate, in that order. Ammonia and nitrite are highly toxic for your fish after prolonged exposure. A brief period of ammonia and nitrite exposure is inevitable while establishing the beneficial bacteria. Testing your water frequently during this breaking… Read more »


basically i am an ornamental fish desease arresters , feed supliments and maintainance chemicals manufacturer.
this article is help ful to me.


I bought a aquarium in my home I want to know the safety measures how to handle them

Paul R Greenhall

My 100 gallon fresh water tank’s water turns light green within three or four days, even after I’ve replaced the water with new water and replaced the filters. The tank has no gravel or ornaments. It does have leafy plants, and large snails. The fish are five six inch ten year-old goldfish. Any recommendations?


Green water is an algae bloom, the main ingredients are either too much light, and or phosphates, nitrates, dissolved organics, etc. Except for the light, the other factors are caused by overstocking and overfeeding. Check and if applicable, correct any of the following aspects: light issues (is the light correct for plant growth and health/ does it need replaced/ is it too intense). Fertilizers? Is a fertilizer over used, or are the plants showing deficiencies?
Please consider the following:

Tanya Davies

Totally enjoying reading all your information 👍I’m learning so much from this and the knowledge is growing again lol, i use to keep tropical fish many many years ago yet iv forgot all I’d learnt


Love haveing you helping my 55 gallon aquarium. Please send me more information

Nitesh bhatt

Hello I wanted to know actually my fish are dying after every week and I lost almost 4 fish in a week but I still don’t know the reason I lost 4 gold fish can you help me out please ?

That’s not a lot of information to go on, so I will assume you are in the process of setting up a new aquarium. New aquariums go through a process called ‘The Nitrogen Cycle‘. During this process, good bacteria (Nitrifying Bacteria) establishes in the fish tank. Nitrifying bacteria are responsible for breaking down organic waste in the aquarium. The process usually takes somewhere around 2 – 4 weeks to complete. During this time, ammonia and nitrite will spike. This can not be avoided. Both ammonia and nitrite are very toxic to fish and lead to fish death if exposure is… Read more »


Great article. Thanks.

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