How To Clean A Fish Tank

how to clean a fish tank

  This site will walk you through how to clean a fish tank with minimal effort and maximum results.   We will provide some common sense cleaning tips for maintaining an aquarium as well as  industry  hints to make fish tank maintenance easier and less dramatic for the tank inhabitants, as well as for you. With more than fifty years of experience, we have simplified the routine of regular aquarium fish tank maintenance. Whether you have a freshwater aquarium, saltwater tank or a living reef, the steps are basically the same.

On this homepage, you will find some categories that may deal with other issues that may concern you or that you may want to learn more about.  Simply click on the category that you are freshwater angelinterested in and you will find articles that pertain to that category.

We are not trying to include every detailed minutia of maintaining an aquarium on this page, but rather give a broad overview so that the process goes as smooth as possible. Because every tank has different filtration, lighting, feeding patterns, etc. it would be impossible to cover everything. However, in all the years that we have been in this industry, there probably isn’t a scenario that the staff at How To Clean A Fish Tank hasn’t encountered.  We have spent untold amounts of money over the years trying products; some really good, but many were just a waste of time and money.  Everything on this site is free.  We decided to set this site up so that you would feel comfortable not only in the knowledge that we offer, but in the confidence you gain in this hobby.  So please take advantage of the contact page to pick our brains. Give us a brief description of the issue that you have and we will get back to you.

percs in anemoneWe understand that this industry tends to have a lot of opinions on how to clean a fish tank as well as aquarium keeping.  The following steps will provide some basic information for the aquarist who wants to learn to do regular maintenance of their fish tank or reef tank. Though some of the employees of Petco or Petsmart or even your local fish store may have valuable experience and can be helpful, all too often this is not the case. With very few exceptions, stores will try to sell you products to “improve” or “correct” problems that you might be having in your tank whether you truly need them or not. Let’s face it, they are in business to make money. We get that. However, many products that are sold to correct water conditions can actually make things worse. Some can even cause a false reading when you test the water — i.e. test says nitrates are zero when they may actually be extremely high. The truth is, regular water changes provide the healthiest possible environment for your tank inhabitants. Most aquarists that do regular water changes seldom, if ever, need to use medicines or water conditioners. Although doing a monthly water change may seem like a chore, it will cost a lot less in the long run than medicines, conditioners and the replacement of dead fish. How to clean a fish tank isn’t rocket science, even though some stores may want you to think that it is.  We call that “job security” for them.  That way they can sell you items.  We hope the following helps.

* Why does an aquarium or fish tank need regular maintenance?

Poor water quality will effect fish, corals, and invertebrates more than any other thing that can happen to an aquarium. Most diseases, algae issues, and fish lethargy can be corrected or avoided with regular water changes. Even if the water is “crystal” clear, that doesn’t mean the water is not toxic. An established aquarium should have zero ammonia and zero nitrites. Nitrates, much less toxic than ammonia or nitrites, will build up over time and become very toxic as well. The easiest way to avoid high levels of nitrates is to do consistent water changes. The physical removal of the old aquarium water is the best way to removes nitrates. The replacement of new, clean, water should cut any nitrate levels in the aquarium by at least the same percentage as the water that is being changed.

full reef

* What causes poor water quality?

Inevitably, the leading culprit for toxic levels of ammonia, nitrites and/or nitrates is over feeding. Though the most likely cause is “killing them with kindness” with too much food, overfeeding can also be the result of too many nutrients frozen food(usually liquid supplements for corals or invertebrates). Overfeeding is a result of people thinking that their fish needflake food multiple meals per day. The truth is that fish will eat what they need within five minutes once per day. So when you feed, the best way to avoid overfeeding is to watch them eat. If, after five minutes, there is any food left, you fed too much. The next day, feed less. When it comes to nutrients, cut the recommended dose by half unless you have an unusually high density of corals or invertebrates.

* How to clean a fish tank with minimal mistakes?

Use the “plus or minus two” rule. A 25-30% monthly water change should never change the temperature of the water by more than 2 degrees.  If it’s a saltwater tank make sure that the specific gravity is not altered by more than .02 (example: if you keep your specific gravity at 1.021, don’t lower it below 1.019 or raise it above 1.023). The “plus or minus two” rule also applies to pH – – never raise or lower pH by more than .2  If any of these conditions need to be changed even more, then wait at least two hours before making any other adjustments. This allows the animals to acclimate without throwing them into shock. Do not remove animals from aquarium.  The stress caused by trying to catch the fish can cause them to go into shock.

* How to clean a fish tank?

1. Got Stuff

Before you start, make sure that you have everything you need.  You should have any salt that you need, both for saltwater or reef aquariums, as well as any that you might use for a therapeutic level in your freshwater tank. Make sure that you also have any filter pads, carbon, air stones, airline tubing or any other products that you might need to clean or replace in the filter system. Once you start the routine of cleaning your aquarium; you don’t want any unnecessary delays in completing the task. Unplug pumps, heaters, lights, chillers, dosers, or any other electrical items that might cause electrical shock while working around water.

2. Decoration Cleaning

If there are decorations that need to be cleaned, remove those items and begin the process of cleaning in a sink, bathtub or other suitable container. Always look to make sure no fish, crabs, shrimp, etc. are hiding in the decor. Most fake plants and decorations can be bleached (that’s right bleached) in a 15 to 20 percent solution of bleach…plain bleach, not perfumed or gel type. After the items are clean, usually only a few minutes, rinse items thoroughly with fresh water. After the decorations are rinsed, submerse items in fresh water and use several drops to several squirts of Dechlor. dechlorDechlor will eliminate any residual chlorine or chloramine left after the bleaching. It usually only takes a few minutes of soaking in Dechlor to do the trick. Rinse items briefly in fresh water once more. A quick sniff of the decorations will tell you if the Dechlor process needs to be done again. If you do smell bleach, it’s most likely that the bleach solution was too high. Next time use less bleach.  Always wear gloves so as to protect your skin from the bleach. Never use soap or detergents on aquarium products.  Now is a good time to check the filter system and replace or clean any items that are needed. It should be noted…we are not going into filter specifics only because there are too many to try to cover and spend adequate attention on.

3. Prepare New Water

kent saltIf you have a saltwater tank or a reef aquarium, mix up the amount of saltwater that you might need. Keep in mind the temperature of the aquarium as well as the specific gravity. Most municipal water is acceptable to mix with high grade synthetic salt mixes. If you are worried about the water from your tap, use Dechlor to neutralize any chlorine or chloramines that might be present. Remember—only put enough Dechlor, Amquel, Novaqua, or even therapeutic levels of salt for freshwater aquariums, for the amount of new water that is going in. The existing water in the fish tank doesn’t need it. In other words, if you have a 100 gallon tank and are doing a 30 gallon water change, only put enough product for the 30 gallons. Don’t use whatever salt is on sale. Your aquarium inhabitants rely on you for consistency. Always try to use the same brand of salt. You’ll find that it is not only less stressful on your fish but less difficult for you. We like to use two trash cans (again, only for aquarium use) for water changes. One can to premix salt before the removal of the old water, and one can to use for actual removal of the old water. That way, you know how much to take out and you won’t waste salt or water. If you have a freshwater tank, it’s still not a bad idea to have two buckets—this way, as you fill the new water container, you can manipulate the temperature and add any conditioners before it goes into the tank.   All too often, people will start putting the water in straight from the tap, not realizing it’s too cold or too hot until it’s too late. ph levelsAlso, if you have a whole house filter that uses rock salt to soften the water, bypass it during the water change. Water softeners tend to change the pH and affect the tank too much. If your fish require softer water with lower pH, like Discus, then use products from your local fish store to achieve that feat.  Quick note: The other benefit of using trash cans is that they are stackable and you can store most, if not all, of the rest of your cleaning equipment along with extra filter pads, cartridges, salt, carbon, etc. with a lid to keep out dust or other contaminants between water changes.

4. Clean Interior Of Aquarium

algae padOk. Wipe down algae from glass or acrylic with proper scrubber as to not scratch the inside of the tank. Remember, the more scratches, the more places for algae to grow. Even though most algae scrubber manufacturers make glass and acrylic scrubbers, we use only acrylic scrubbers.  That way the likelihood of scratches is greatly diminished.  Also, the majority of acrylic scrubbers are white, which allows for easy sight of the smaller algae spots.  Take the time to wipe down any algae that might have accumulated on powerheads, heaters, undergravel stacks, remaining decorations,etc. If the algae is extreme, you might want to “net” out as much as possible. A lot of algae is a sign of too much light, too many nitrates, or a combination of both.  Never use anything toxic to clean the interior of an aquarium.

5. Remove Old Dirty Water

Let’s start the removal of the aquarium water. Before removing the water, check to see if any thing that is alive will be gravel vacuumexposed when the water level drops during the water change. This last point mainly concerns corals, anemones, etc. If there are animals that will be exposed, carefully place them lower in the tank or even on the bottom if needed. You will be using a gravel vacuum to siphon out 25 to 30 percent of the volume of aquarium water. Make sure that you use a gravel vac that is suitable for the size tank you are working on. Too large of a vac on a small tank will siphon too quickly without properly removing detritus (dirt, algae and debris). Too small of a vac on a large tank will not remove water quickly enough or efficiently. The key is to remove the waste material and loose debris without sucking up the substrate (gravel, crushed coral, sand). After a few times, you’ll get the hang of it. If you’re not sure how to properly vacuum the materials from the tank, there are many videos online that can show you easily how it is done.

6. Replace Decorations

freshwater decorationsNow that you have removed the 25 to 30 percent of aquarium water that needed to be changed, it’s time to replace any decorations or plants that were cleaned.  We find that is easier and less water will be splashed around by placing these items in before the new water is put back in the aquarium.


7. Refill Fish Tank With New Water

The old water is now out, the tank is decorated the way you and the fish like, so it’s time to put the new water in. If you have a pump, make sure that when you start it, that it won’t splash everywhere and that the force of the water won’t harm aquarium inhabitants.  Depending on the size tank that you have, it can be well worth the money to get a small pump and some tubing or a hose that you only use for cleaning your fish tank. It makes draining the old water out and replacing the new water much quicker and saves the carrying of buckets back and forth.  The pump doesn’t have to be huge or expensive. It only needs to pump an adequate amount of water for the heighth of your tank. Note: most pumps will have a graph or chart on the box or in the paper work that shows how many gallons it will pump at various heighths. Bring water levels to where they should be, both in the tank and the sump or filter. Once you have the water level where it needs to be, plug in the electrical items that you had unplugged at the beginning.

8. Almost Done

Make sure that all of the electrical items are functioning properly and make any adjustments that may be needed to temperature control devices; heaters and chillers. Watch pumps and filters and make any flow adjustments or water wet dry filtersoverflow filterlevel adjustments that may be necessary.  Wipe down outside of tank to clean off water marks or finger prints. We always use a wet towel first, then a dry towel.  These can be paper towels as long as they aren’t too rough.  Rough paper towels can scratch acrylic.  If you need something stronger than just wet and dry towels to remove something from the outside of the tank (sticky hand prints from the kid next door), spray the cleaner on the towel first, away from the tank.  Then use dry towel.

9. Ahhhh

Sit back and enjoy your fish tank.  Now you know how to clean a fish tank. We are very much aware that we did not include every aspect of what can or even should be done in order to show someone how to clean a fish tank or maintain every kind of tank, filter, lighting system, etc.  It would take too much time and still wouldn’t cover every little nuance that you might have regarding your fish tank. We at How To Clean A Fish Tank, rather, decided to help the individual who is trying, perhaps for the first time, to maintain their aquarium with as few problems as possible. This site is provided so that those who aren’t familiar with the necessary steps to clean their fish tank might be able to do so with a modicum of confidence.  Some products were referenced and others were pictured.   These are simply products that we are knowledgeable about and feel comfortable mentioning.  This should not be construed as an endorsement.  We hope this site made you more comfortable on how to clean a fish tank. We hope that the above information was helpful. We welcome comments and questions. will reply to your comments and questions, if necessary, as quickly as we can.  

How To Clean A Fish Tank
Article Name
How To Clean A Fish Tank
A guide to assist any aquarist in the regular maintenance of a fish tank. This site offers professional know how for the safe and efficient routine cleaning of fresh or saltwater aquariums.

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