How To Keep Clear Water In An Aquarium

I love having aquariums and I enjoy giving tips on how to maintain them.

If you choose to go with live plants, you will find that over a year or two, your aquarium will reach a steady state of being, ecologically.

Preparing Your Aquarium for Minimal Maintenance

I often get questions about how to keep a fish tank clearer for a longer period of time. Let's face it: Water changes can be tedious, messy, and time consuming. Caring for my own aquariums, I have gone from the dip-the-cup method to the siphon-into-the-bucket method to the Python hose method, which connects directly to a faucet or spigot to drain, siphon, and fill. In my opinion, the latter is the least time consuming and messy. But wouldn't it be great to go two to three months in between water changes (instead of one month) without harming the fish and livestock in your aquarium?

This isn't easy—at first. Your aquarium must be prepared for the change. All of these elements play a part in the cleanliness of your aquarium:

Filtration
Decorations
Fish residents

If you do your research and follow the general guidelines here, you will be able to help your aquarium reach a steady state of being, giving you an ecosystem that can survive with minimal maintenance.

All types of filters—submersible, hang-on, and external—are great choices. Pick one that is easy to use and that will be most practical for your aquarium.

Step One: Filtration

Here is what you need to keep in mind about filtration.

Considerations When Choosing a Filter

First, let's talk about the filtration system in your aquarium. Three primary factors need to work together to keep an aquarium clean:

Chemical: Carbon, charcoal, and zeolite can convert toxins in the water chemistry.
Mechanical: Cotton or foam cartridges that physically remove debris from the water.
Biological: Nitrate-forming and nitrite-forming bacteria are produced by fish waste, and a good balance of both is vital to a healthy aquarium.

When choosing a filter, there are many different types of filters to choose from:

Submersible
Hang-on
External

All are great choices. Pick one that is easy to use and that will be most practical for your aquascape environment.

It is ideal to choose a filter at least one size bigger than the tank's capacity. For example: If you have a 55-gallon aquarium, you would need a filter for a 60–75-gallon aquarium, and preferably with a substantial carbon media and bacteria bed.

Installing Your New Filter

The mechanical part of the filter can be changed at any time, but the chemical and biological filters need a break-in period so they can perform as expected. When you get ready to upgrade your filter, you want to to put the new filter on your aquarium for at least three weeks with the old one still in place. This gives the new filter time to build its own bacteria bed and the charcoal and carbon time to activate.

You also need to make sure your chemicals are adjusted appropriately, meaning your nitrates, nitrites, and ammonia levels need to be stable. There are inexpensive tests available to perform this test. If the levels are out of balance, I use Stress Coat (a chlorine reducer) and Stress Zyme (a bacteria booster to help the process along), but only time can ensure stability for your aquarium. Once you are sure your water is safe, you can remove the old filter.

If you like the idea of plants with your African Cichids, plant the fauna well before you add the fish to ensure proper rooting.

Step Two: Decorations and Environment

If your aquarium gets dirty very quickly and is difficult to clean, the type of décor you have in your tank might be adding to the problem. Some types of décor need more frequent care than others. Plastic plants, rocks, and other knick-knacks will need to be cleaned periodically, while river rocks and the live plants don't need to be cleaned as often.

Also, consider whether your choice of décor is appropriate for your fish. Do your décor items contribute anything of value to your fish or are they purely aesthetic? I prefer natural environments and have live plants in all of my aquariums (nine total, currently). Here are some advantages to a natural aquascape:

Plants help your water quality in more ways than you think. The plants help convert the nitrites into nitrates. Some fish, like guppies, Angel Fish, and Discus, for example, need to be in an environment with live plants and a steady flow of water.

Step Three: The Right Type of Fish for Your Aquarium

There are many species of fish to choose from.

Cold water varieties like goldfish, carp, and koi.
Tropical species include African cichlids (three different lakes in Africa give us a beautiful selection and come closest to providing the colors that saltwater fish do).
South American cichlids come in an array of sizes and have an iridescent yet graceful display.
Tetras come from different regions of the world and are easy to mingle together.
Gouramis, mollies, platies, guppies, barbs, sharks and catfish are among the numerous varieties of community fish (with different levels of aggression).

The rule of thumb is to have one individual fish per one gallon of water for a healthy size ratio in your tank. I personally like to have more fish and a bigger filter. Then, I can usually get away with having one fish per gallon. It's important to stock the aquarium safely for the fish and appropriately for the species you may have.

Some fish like to swim in alkaline water, and some prefer a softer water environment. Test your tank's pH levels for sensitive fish such as neon tetras, angelfish, and discus.
Tropical or freshwater fish live and eat in various areas of the world and different levels of water depth. Make sure your fish are compatible with each other, or you will have carnage and dead fish clouding up the water.
African and South American cichlids require different aquarium décor and have different water needs than guppies, mollies, or tetras. They are much more aggressive than goldfish and gouramis.

A variety of foods helps maintain your fishes' color, growth, and overall health.

Step Four: Feeding Your Fish for a Clean Tank

How you feed your fish also plays a role in how easy is it to keep your aquarium clean. Different fish have different diets: some eat other fish, some eat veggie diets, and there is a wide variety of flakes and pellets to keep your fish from starving to death.

Providing your fish with a variety of foods helps maintain their color, growth, and overall health. Remember: The more you feed them, the more they poop. Only feed them what they can consume in two minutes, and there will be less waste. This will reduce the amount of ammonia in the water. Ammonia turns water a murky yellowish-brown color.

The Result: A Steady State of Being

If you are like me, once you have your tank filter, decorations, fish population, and feeding routine just the way you like it, you will rearrange your aquarium several times before being satisfied with the way it looks. Try not to stress your fish by moving them for two to three months, and you will find your aquarium stays cleaner longer.

If you choose to go with live plants, you will find that over a year or two, your aquarium will reach a steady state (this should be every enthusiasts' goal!). A steady state means that the chemistry of the water in your aquarium is changing slowly if at all. Think of it this way: If your electricity failed and you could not use the filter in your aquarium for a year, the balanced combination of plants and fish would filter the water on its own. The only cleaning you would have to do would be to clean the algae off the sides of the glass and change the water four times a year.

I hope you have found this helpful and time-saving so you have more time to enjoy your aquarium instead of maintaining it. Enjoy and thanks for reading!

Bantu on March 27, 2020:

My gold fish tank very cloudy at all time how maintain water clearity

FishLover on May 28, 2019:

This information is completely incorrect for goldfish. A common or comet goldfish (single tail) requires a bare minimum of 40 gallons then 20 gallons for each additional goldfish. Fancy goldfish (bigger tail) require 20 gallons per fish and 10 gallons for each additional fish. Koi fish are not aquarium fish, they are pond fish. Commons and comets should be in a pond as adults... people are so misinformed about these fish.

Annie Mc on January 24, 2019:

I have 55 gallons tanks 6 koi goldfish ,4 algea eater ,10 small goldfish ,I have two big filter clearer with 2 filter in each of them but i have to clean my tank every two week wash my filter every two days. I have 20 gallons tank it has 2 small catfish 3 black papa eye 2 mixer color 2 gold papa eye 2 algea eater .I two filter clearer. I have two much money tied up in it with the goldfish I wish i know what i know now when i purchased my fish .please help me. i hear that goldfish is hard to keep clean.

Debra on November 08, 2018:

I have a 125 gallon fish tank and a 46 gallon fish tank the 125 gallon is the one i have the problem with keeping the water clear I have about 25 fish in that tank they are big Koi and goldfish I have 2 inside filter 2 sterlizer and a canister why can't my water stay clear sometime it will be clear and sometime it's not i need some advice please help me

sue on June 24, 2018:

how many time do feed goldfish

Andy wilky on April 09, 2018:

I have just got my fish tank just starting I have put black widows and neons and a baby gupie one of my widows is always near the filter what can ido to help

Sclsunaz on February 24, 2018:

Well thanks for all the answers to the question I posted 3 months ago. I bought a uv light and problem solved.

Debbie on February 16, 2018:

I have a 125 gallon fish tank my water is not clear i just got this tank how can i get my water clear please help

sparton on November 07, 2017:

good idea thank u

sclsunaz on November 02, 2017:

My aquarium has been set up for a few months now and all of a sudden it got cloudy. I can't get it clear. I've tried clarifying chemicals and water changes. It's been a few weeks now and it's driving me and the cichlids nuts. I'm not sure why they are still alive. I tested the water just now and it's the same as it was before water change

GH 60 KH 80 PH 7.0 NO2 0.5 NO3 20

I dont know what to do. I have a sun sun canister filter it's the one that doesn't have the uv light I'm thinking about buying one and see if I can get it clear. The water I still cloudy but the water in the canister is green so that's algae right? It is on the inside wall and the sun does not even come close to it.

I've heard baking soda and Edson salts are one way to get water perfect for my fish 1 teaspoon per 5 gallons.

Help.........

Kelly on October 01, 2017:

I just got a new 65 gln aquarium and I have koi in it. I only had it for a week now and the water is greenish and murky. I can't get it clean. I did a 25% water change and added a clarfier but it just looks awful. I read about filters needing to cycle, how long can I expect this water to look like this and is it safe for my fish? I have 3 live plants and 3 structures.

Gary the Snail on September 18, 2017:

My beta aquarium never had a problem with algae until we added live plants. They made the tank so dirty that I had to get rid of them. I would recommend sticking to plastic plants if you don't want to clean as often.

jajajaja on January 27, 2017:

can the breather affect the steady flow of water in the aquarium? how many times would you feed your fish?

Anonymous Mermaid on December 28, 2016:

You are an organized writer! Wow! Thanks so much. It was detailed, sequenced, and easy to follow! :)

Nivas from Salem on September 10, 2015:

Good one....!!