Should you try cleaning your tank without emptying it or just tear it down and start from scratch? This is a question that gets posted quite often.

If you tear it down you will lose all the beneficial bacterial colonies that breakdown the wastes produced in the aquarium. For that reason I wouldn't start over, unless your tank is in extremely bad condition. With a little elbow grease and a few simple cleaning supplies you can have your aquarium looking ship shape again. Here are the supplies you'll need:

I suggest cleaning your aquarium in the following order:

Why clean the tank in that order?

Cleaning the glass will cause particles of debris to fall on the plants, decorations, and gravel, so it's best to clean them after the glass has been cleaned. Removing the plants and decorations will cause debris to fall to the bottom, so you might as well hold off cleaning the gravel until the plants and decorations have been taken out. Also, the gravel is much easier to clean once the plants and rocks have been removed. Needless to say, cleaning anything inside the tank will cause the outside of the tank to get dirty, so the outside should be cleaned after the inside. As for the filter, read on to see why that is the last item I recommend cleaning.

Algae Pads/Scrapers

Start your cleaning project by giving the glass a good cleaning on the inside. All you need for that is an algae scraper or pad. There are a wide variety of algae scrapers on the market, from long handled scrubbers to magnetic scrubbers. I personally like the small magnetic scrubbers, however virtually any algae pad will do. People often ask me if it's necessary to purchase algae scrubbing pads at a pet shop instead of the house wares department of a regular store. Although the pads may look the same, they may have a soap or chemical residue in them from the manufacturing process. A residue doesn't matter if you are cleaning your kitchen sink, but it can leave a lethal film in your aquarium. For that reason, I advise spending a few extra pennies to get the algae pads labeled for aquarium use. For particularly stubborn residue on the glass, use a razor blade to scrape it off. Take care not to cut yourself, or scratch the glass. If your aquarium is acrylic, use a special plastic razor blade, as standard razors will scratch acrylic.

Bleach ( see Note at Bottom )

Once the inside glass is clean, remove any rocks, artificial plants, or decorations that have significant algae growth, or are noticeably dirty. Do not clean them with soap or detergents! It is very difficult to completely remove soap, and even the smallest trace can be lethal to fish. Usually a good scrub with an algae scraper will remove the algae and dirt from rocks and plants. For particularly stubborn cleaning problems, prepare a 10% bleach solution (1 part household bleach to 9 parts water) and soak the items for 15 minutes. Scrub any remaining residue off, rinse well in running water, and let air dry to eliminate any residual bleach.

Live plants can be bleached, however stem plants do not tolerate bleaching well. To bleach live plants prepare a 5% bleach solution (1 part bleach to 19 parts water), soak the plants for two to three minutes (no longer), then rinse well.

Leave the rocks, decorations and plants out of the tank while you vacuum the gravel. That way none of the debris stirred up from the gravel will settle on them. A word of caution - get a new bucket and designate it for aquarium use only. If you use a bucket that has had soap or detergent in it, you risk introducing chemicals to the tank, which could result in the loss of your fish.

Siphon

Clean the gravel next, by using a water siphon to vacuum away the debris. There are several types of siphons available, all of which work essentially the same. My preference is for the Python, because it draws the dirty water directly into your sink, thus eliminating the need to use buckets (which can easily be tipped over). Magnum makes an adapter for the Hot Pro unit that allows you to siphon water through the filter and return it right back to the tank. Although this works well for removing larger debris particles, smaller particles will pass through the filter and are returned to the tank. Be sure to vacuum the entire surface of the gravel thoroughly so that all debris is removed.

Glass and Lime Cleaners

Once the inside of the aquarium is cleaned, the hood, light, tank top, and outside glass can be cleaned. I strongly urge using cleaners designated as aquarium safe. Regular glass cleaners contain ammonia, which is toxic to fish. Standard lime cleaners are even more toxic. Use aquarium safe cleansers, and rinse rinse rinse!

( I like using safe and easy wipes. You can find them here. ed. note )

Safe & Easy^TM Aquarium Wipes

Filter Cleaning

Once everything is clean on the inside, the rocks, plants, and other decorations may be returned to the tank. At this point I'd wait a couple of weeks before cleaning the filter. Why wait? The reason is not visible to the naked eye. The major cleaning you just performed has disturbed the bacterial colonies on the plants, rocks, and in the gravel. Fortunately a significant number of the beneficial bacteria reside within the filter media, so you haven't completely upset the eco-system. However if you changed the filter at the same time, you might end up with a significant ammonia spike because there aren't enough beneficial bacteria left to eliminate the toxins. For that reason, it's wise to give the tank a rest before removing the filter and cleaning it.

When you are ready to clean the filter, should you clean or simply replace the filter media entirely? Some experts caution that replacing the filter media removes too many of the beneficial bacteria, and can essentially throw the aquarium into a new tank break-in cycle. Other experts argue that there are sufficient bacteria on the rocks and plants, and in the gravel to prevent the tank from having to go through a break-in cycle when the filter is replaced. My viewpoint is that what you should do depends on the type of filter media you are using.

If you have filter media containing carbon, ammonia absorbers, or ion-exchange resins, it should be replaced if it's more than three weeks old. After a couple of weeks the absorbing qualities in the media have been exhausted, and there are enough bacterial colonies elsewhere to offset its removal.

Media that acts as a mechanical filter instead of absorbing toxins (i.e.: ceramic rings, filter fiber, or sponges) should be gently rinsed to remove debris and returned to the filter. If care is taken to use water that is the same temperature as the aquarium water, and the media is quickly returned to the filter, the bacterial colonies growing on them will not be lost entirely.

Don't forget to clean the filter tubing and other parts of the filter assembly. A filter brush will help clear out the sludge that invariably builds up in all the small crevices.

Ongoing Maintenance

Once you've gotten your tank in shape, make sure you clean it on an ongoing basis so it never needs a major spring-cleaning again. Scrape the glass weekly, vacuum the gravel every time you perform a water change, and clean any rocks or plants as soon as you see debris or algae on them. Clean the filter monthly, either by replacing the media, or rinsing it. While you are at it, soak your fish nets in a disinfectant solution to keep them clean and soft. With regular care, your aquarium will look beautiful all the time.

Shirlie Sharpe,
Freshwater Aquariums.

Several alert readers have sent emails cautioning the use of bleach as it can be a very toxic chemical. ( all you CSI fans are duly noted )  Shirlie's article stresses the importance of diluting the bleach to specific levels to avoid toxicity. Bleaching should probably be done only as a last resort and only if you are confident that you can mix the ratios properly. Proper scrubbing should solve most of your issues. A less polite individual might suggest that if you have to resort to bleaching then maybe you haven't been keeping up with your cleaning... tsk tsk.

A special thanks goes out to Gabrielle for pointing out that bleach can be detected on clothing even after several washes. I liked her cautionary email and have added it below,

Thanks to everyone for all your helpfull emails - keep them coming so we can all learn together!