Sometimes, despite your best efforts, life gets in the way and your aquarium gets out of control. Every day you tell yourself you’ll get to it and all of a sudden it’s too late. You start thinking that it would be better to empty the whole thing, throw everything away and start from scratch. It’s happened to me before, believe me. But stop! Before you give in to temptation… if you tear it down you will lose any beneficial bacteria that have colonized your fish tank. Only if your tank is in severely bad condition, it may be worth having to start over.
Now, if you find yourself with the need of having to clean a very dirty fish tank, you’ll need a few tools. Don’t despair, you can do a great cleaning of a dirty tank without losing your good bacteria colonies. It may take a little effort and time, but you’ll be rewarded with a sparkling aquarium and happy fish.   So, let’s get ready for battle.

These are your weapons:

•  Algae scraper or scrubbing pad

•  Plastic razor blade (use plastic on acrylic tanks)

•  Water siphon

•  Bucket

•  Bleach

•  Aquarium glass cleaner

•  Filter media

•  Filter brush

•  Paper towels

•  Old bath towels

You’ll find cleaning easiest if you do it in the following order:

1. Inside of glass

2. Decorations

3. Gravel

4. Outside of glass and hood

5. Filter

First of all, remove your fish and any other creatures that live in your aquarium. Place them in a container that is reserved for fish only using water removed from the tank. Be careful where you put them. It’s always good to have a bucket dedicated exclusively to your fish tank, for carrying the water when you change it, and in cases like this, to put your fish. Make sure you use a brand new bucket. Old buckets may have residues of chemicals or detergents that may get transferred into your aquarium.

The inside of the glass

Take one of your algae scrubbing pads and clean the inside of the glass. You can find many types of scrubbers at the fish store. Some have handles, some are just pads. Some have magnets so you don’t even need to put your hands into the water because they work through the glass, but these are better for maintenance than to do a thorough cleaning. While you may see scrubbers at the fish store that look just like the ones you can find in the supermarket or in your kitchen, get the ones from the fish store, NEVER use any other kind of scrubber. Household scrubbers or sponges may contain soap or chemicals that will kill your fish.

If you have some residue on the surface that is resisting the scrubber, you can use a razor blade. If your tank is acrylic, be sure you get a plastic razor blade, since a standard one will scratch the acrylic.
Decorations

Remove any rocks, decorations and artificial plants that are covered with algae or look dirty.

Again, NEVER use soap or detergents on these items! It can prove lethal to your fish. Scrub them with your algae scrubber. This will remove most of the algae and dirt. If you have some particularly hard to clean spots, you can soak them in a bucket containing a 10% bleach solution. Let the items soak for 15 minutes, then scrub off the stubborn spots. Rinse the decorations really, really well with running water and let them air dry.

You may be surprised to learn that live plants can also be bleached, if needed, with the exception of stem plants. Live plants should have a 5% bleach solution in your bucket. Soak the plants for only 2 or 3 minutes. Rinse them off really well in running water.

The Gravel

Vacuum the gravel in the aquarium with your aquarium siphon. You can get one that you can connect directly to the fawcet in the kitchen, siphon the water out, and use the same hose to fill the tank again. Vacuum the gravel thoroughly until the debris and the dirt is gone. I have almost ran out of water and there still a lot of dirt, but I just pour more water in and siphon it out until it’s better.

The Outside of the Glass

Now it is time to clean the hood, the lights, the top of the tank and the outside of the glass. Don’t use normal glass cleaners… they contain ammonia. If you are tempted to use lime cleaner, or any other commercial cleaner, stop! They are very toxic to fish. Get a cleaner from the fish store creater just for this purpose or use vinegar. And remember, rinse really well afterwards, and then rinse it again! Even when you clean the outside of the glass, you have to be really careful, better not to risk it.

Cleaning the Filter

Now that most of your tank is done, you can decorate again and put your plants back in. Don’t clean your filter yet… wait a few weeks. I know you may be in the middle of a cleaning binge now, but refrain from touching your filter. Cleaning your tank has disturbed your colonies of beneficial bacteria. Luckily, they also live in your filter media. Cycling the new water through your filter will help repopulate the tank. If you clean your filter at the same time you clean your tank, you may cause an ammonia spike that can be lethal to your fish.

Okay, now its a few weeks later and it is time to clean your filter. Do you just replace the filter media or do you clean everything? Depending on the type of media you use, the answer may be different. If your filter media is made up of ion-exchange resins, carbon or ammonia absorbers, replace it if it has been in the filter for more than three weeks. The media is exhausted by this time, and no longer provides the benefits it did before. Mechanical filters like sponges, ceramic rings or fiber can be rinsed lightly to remove dirt and debris while leaving the bacteria somewhat intact. To protect the bacteria, use water the same temperature as your tank and return the media back to the filter immediately.

You should also clean out the tubing and other pieces of the filter assembly. You can use a filter brush to remove any sludge or debris that has built up in crevices.

Create a Maintenance Schedule

Now that your tank is beautiful again, give yourself a simple maintenance schedule so you don’t have to spend all day doing a major cleaning again. Do partial water changes every couple of weeks, remove algae on the glass and décor every week or as soon as you see it. That’s where the magnets come in handy. Do filter cleaning every month as described above. You can also keep your fish nets in great condition by occasionally soaking them in a bleach solution and rinsing them extra well to keep them clean. Your aquarium will become your new pride and joy and you’ll be able to enjoy your fish once again.