How To Test Fish Tank Water Without A Kit7 mins read

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How to test fish tank water without a kit
Image from Flickr

One of the most important facets of owning an aquarium and tropical fish is ensuring that the correct water parameters and temperatures are kept constant for the specific species of inhabitants in the aquarium. Essentially a well-cycled aquarium that has been running for some time, and that generally looks healthy and clear, with healthy and vibrant fish should not require such regular parameter checks. However, a new aquarium that is younger than six months, or after doing a clean or water maintenance, may validate the need for proper water parameters and temperature checks.

If a proper testing kit is not at hand when needed, or even for new Aquarists who have not gotten as far as obtaining a testing kit, there are a few alternative measures that can be taken to test the water and ensure that water parameters are at optimal levels.

However, before getting into that, it will be crucial eventually to invest in a testing kit, as the methods described are a temporary and not a permanent solution to rely on.

The Importance Of Proper Water Parameters In Your Fish Tank

Before getting to the question “How do I test my fish tank water without a kit?”,  it is necessary that the reasons why water parameters in an aquarium are so important are well understood.

The health of your aquarium inhabitants depends on maintaining proper water parameters. Routine testing is the only accurate way to ensure certain water parameters are within an acceptable range.

Basic Water Parameters

Basic water parameters
Though not entirely part of testing water parameters, for tropical fish, tropical water temperatures are required. Image from Flickr

There are a few water parameters which you will mostly need to test for:

1. Temperature

Though not entirely part of testing water parameters, for tropical fish, tropical water temperatures are required. Some freshwater tropical fish need very consistent temperatures to flourish. Unfortunately, the best way to ensure that water temperatures are correct and consistent is to use a thermometer and heater. Most internal heaters, luckily, have a built-in thermometer.

Generally, most freshwater fish species will flourish in temperatures between 22 – 28°C or 72 – 82°F, some species requiring higher, and other species such as Goldfish and Guppies enjoy cooler water temperatures. The most important factor is to always keep temperatures as stable as possible for tropical fish especially.

2. pH

Water pH is the measurement of how alkaline or acidic your tank water is. Specific aquarium inhabitants require specific pH ranges, some species prefer slightly more acidic water, while others prefer high alkalinity. A pH of between 6.0 and 7.0 will be more acidic, whereas higher than 7.0 will be more alkaline. Though for most tropical freshwater fish species pH levels between 6.5 and 7.5 are usually acceptable. Once again in terms of pH levels, stability is the key element, as rapid changes in pH can be fatal for some fish species.

  • How to Lower pH – A natural method to lower pH levels in your tank is to add peat moss to the filter, or to add Catappa leaves to your aquarium. Other than that, it can be done with chemicals.
  • How to Raise pH Levels – To raise pH levels and make water more alkaline, some baking soda can be added to your tank. One teaspoon per 5 gallons will create a small and safe increment. Similarly, never increase the pH levels rapidly.

3. Ammonia

Ammonia is an extremely toxic substance that is mainly created by the decomposition of fish waste, leftover foods, and other organic substances. A tiny amount of Ammonia in your tank can destabilize the biological balance of an entire aquarium. Ammonia spikes in your tank most certainly lead to illness and even death of tropical fish species. It is crucial to always measure Ammonia levels in your tank. Ammonia and Nitrites should never be traceable in your aquarium after it is completely cycled. With that note, an important factor in any aquarium is what is called the Nitrogen Cycle.

Nitrogen Cycle. Image from Wikipedia.

Nitrogen Cycle is a term that is used many times by aquarists, and an important factor in keeping proper water parameters. When Ammonia, which is a toxic nitrogen compound is consumed by microorganisms, and beneficial bacteria from plants, substrate, filter media, driftwood, and other tank items, turns Ammonia into less toxic nitrites. The beneficial bacteria similarly feed off the nitrites and produce nitrates which are the least harmful.

Cycling your aquarium means that there is enough biological filtration such as beneficial bacteria to eat all Ammonia and Nitrites. Removing and replacing water in your tank weekly will similarly help to keep nitrite and ammonia levels down. Ideally, your tank should have 0 ppm ammonia, and 0 ppm nitrites.

4. Carbonate Hardness / Alkalinity (KH)

Carbonate hardness in water refers to the measure of dissolved carbonates and bicarbonates in your tank water. The Carbonate hardness of your aquarium water helps to maintain a stable pH and buffers acidity. A degree of Carbonate Hardness (dKH) above 4 or 17.9 ppm is advisable to prevent pH levels from crashing. Beneficial bacteria in your tank naturally consume Carbonates, though the substrate will help to generate more.

5. General Hardness (GH)

General Hardness (GH) mainly refers to calcium and magnesium along with other metal ions detectable in the tank water. Because these compounds are so poorly soluble, they may cause lime deposits in the tank. A dGH of between 4 and 12 is suitable for tropical fish tanks, depending on the fish species that you are keeping. In cases where you have soft water in your tap, the GH is low, whereas harder water has a high GH.

6. Oxygen

Aquarium plants and fish require proper levels of oxygen to thrive and prevent susceptibility to disease. A proper filter along with live plants, and regular water changes will help to maintain oxygen levels.

7. Salinity

Salinity refers to the amount of salt dissolved in your aquarium. Most tropical aquariums require a certain amount of aquarium salts. Freshwater fish generally require a much lower salinity than marine fish, though there are freshwater fish species, such as Guppies that prefer slightly higher salinity in their water.

Though water hardness, oxygen, and salinity are mentioned as basics, most testing kits, and natural testing methods mainly aim at testing pH and ammonia levels.

How To Test Aquarium Water Without A Kit

fish for a 3 gallon tank
Visible water conditions may similarly indicate a poor nitrogen cycle in your tank, in which case you can use bacteria alternatives or introduce more live plants and decor that contains natural bacteria. Image from

Ideally, every fish keeper must have an aquarium testing kit, and thermometer at hand, whether beginners or even the most advanced aquarist. Though should you not have obtained a testing kit yet, or should there be an issue where testing with a kit is not possible at the time, there are a few other methods you can follow without a kit;

Methods To Test Your Fish Tank Water Without A Kit

1. Visual Testing

Usually, when aquarium water is in poor condition, there will be some visual indicators. Water that looks cloudy, dirty, or even green indicates significant unfavorable water parameters. Mostly a good scrub-down will remove algae buildup, and a partial water change should clear up the water. Visible water conditions may similarly indicate a poor nitrogen cycle in your tank, in which case you can use bacteria alternatives or introduce more live plants and decor that contains natural bacteria.

2. Fish Behaviour

Fish tank water can easily be tested by observing the behavior of your fish, although when they start showing unfavorable behavior it may already be too late, and their health could be compromised.

  • These are the most common behavioral traits in fish with poor tank water parameters;
  • Loss of Appetite.
  • Stress or depression, shying away.
  • Gasping for air at the surface of the tank.
  • Spend most of their time hiding, or at the bottom of the tank.
  • They have red or damaged gills.
  • There are white parasites on them.
  • They are swimming frantically around the tank.
  • Strange swimming patterns.
  • Fish seem weak and lethargic.
  • They are floating on the surface of the tank.
  • There is a sudden change of color in your fish or discolored patches are appearing.

The mentioned behaviors usually indicate poor water conditions and many times Ammonia poisoning that can lead to health issues and even death. The behaviors above could be signs of poor water conditions – or even ammonia poisoning. Intervene with a partial water change right away.

In all honesty Aquarium testing kits will be a much cheaper option than a vet visit or treating sick fish, thus at this stage, it would be wise to do a proper full parameter test with a testing kit.

3. Pet Store Help

Ideally, if you need to do an emergency test without a kit you could always ask for help from a local pet store. Local stores may be able to do a quick test on a sample of aquarium water, for a price usually, if you are lucky for free.

4. Test Strips

If an aquarium testing kit may be out of your budget range for the time being, there is always the option of testing strips. Testing strips are more affordable than full test kits and will give accurate results, fast. Similarly, they are disposable and less of a hassle than a full testing kit.

How To Test Specific Parameters

How to test specific parameters
You can check for condensation to see how cold water is. Water in a Glass or metal container that leads to condensation on the outside means that the water inside the container is colder than the room temperature. Image from Flickr

1. Ammonia

The most accurate way to check for excessive ammonia in your tank is to look at certain characteristics in your fish. If they have a loss of appetite, are lethargic, stressed, and tend to sink to the bottom of the tank, it is a clear indication of high ammonia levels, and a proper water change is vital immediately, along with arrangements to improve nitrogen cycling. The best way however to test for Ammonia is to use a proper API ammonia testing kit, available at most pet stores.

2. pH

The pH of your aquarium water can be tested without a kit; however, the method is not very accurate and time-consuming. For the test, you will need a red cabbage and a glass bowl. Grate some of the cabbage and boil two cups or 470ml of distilled water. Place the grated cabbage in the glass bowl and pour the boiling water over it. After 30 minutes strain the water and you will have a testing solution. You can pour a few drops of cabbage juice into a sample of aquarium water. If that water turns pink it is more acidic, if the water is a deep violet color the pH is around 6.0. A bluish color indicates that the water pH is around 7.0 and green indicates a pH of between 11 and 12.

3. Temperature

There may be some point where you need to check the temperature of your aquarium water, and if you do not have a waterproof thermometer on hand, there are other methods that will not give a precise degree of heat, but at least an idea for the time being.

  • Using hand or Elbow – For a rough idea hold your hand above the water, if you feel the heat radiating it is too hot and will burn, if you feel no heat, it will either be room temperature or cold. You can dip your elbow into the water to tell if it is hot or cold. Holding your elbow in the water for 5 – 10 minutes it should feel slightly warm indicating a temperature of around 100 °F (38 °C), and cooler for lower temperatures.
  • Bubble Test – When heating water in a pan or pot, small bubbles will start to form at the bottom indicating the temperatures are roughly around 160 °F (71 °C), medium-sized bubbles indicate a higher temperature of around 175 °F (79 °C), Continuous chains of bubbles will form and start rolling when the water is at boiling point, around 212 °F (100 °C).
  • Testing Cold Water – You can check for condensation to see how cold water is. Water in a Glass or metal container that leads to condensation on the outside means that the water inside the container is colder than the room temperature. Condensation will form faster as the water becomes colder. In most cases, water that is cold enough to cause condensation will be too cold for tropical or even cold-water freshwater fish.

Proper Fish Tank Set-Up And Maintenance

Proper fish tank set-up and maintenance
As a result, proper aquarium set-up, a thorough nitrogen cycle, and regular cleaning and maintenance form an integral part of keeping your aquarium clean, and fish healthy and thriving.

As a result, proper aquarium set-up, a thorough nitrogen cycle, and regular cleaning and maintenance form an integral part of keeping your aquarium clean, and fish healthy and thriving. A few good housekeeping tips for your aquarium include;

Weekly water changes, replacing between 25 – 30% of your tank water, siphoning it from the bottom, and adding new treated and heated water with the right parameters.

  • Remove any dead fish or plants immediately.
  • Changing water should it become cloudy.
  • Do not overfeed fish, and remove uneaten food.
  • Do not overcrowd your aquarium and stick to the correct ratios for the tank size.
  • Only fill your aquarium ¾ of its capacity and not full.
  • Do not just use one type of food over and over.
  • Use an aquarium lid, or cover.
  • Only change water if it shows discoloration or the fish show signs of distress, and unhealthy behaviour.
  • Invest in a proper filtration system.

Ideally, eventually, you will need to purchase a proper testing kit.

Final Thoughts

As can be noted from the gathered information, there are a few methods to test water parameters even water temperatures without a testing kit or thermometer. However, not all of them are accurate and reliable, and you will only be able to gather rough data or assumptions from most. Thus, it is crucial to have a proper testing kit and thermometer to keep your fish healthy and content, and to keep optimal water parameters.

Frequently Asked Questions

How Can I Keep Safe Water Parameters Without a Kit?
By following the “Housekeeping” methods in the Maintenance section, you can essentially keep safe water parameters without a testing kit. Ensuring that your tank is initially properly cycled, doing regular water changes, feeding a proper diet, and investing in a proper filter can keep the water clean and healthy.
How to Test Ammonia Levels Without a Test Kit?
You should be able to easily notice ammonia spikes in your tank when fish become stressed, lethargic, and show physical signs of damage such as red gills. Tired, and bottom swimming fish are similarly a clear indication of ammonia buildup.
How Can I Reduce Ammonia Levels Naturally?
The best method to reduce ammonia levels in your tank as fast as possible is to do a water change and filter and cycle your water with beneficial bacteria. Try not to overfeed your fish, and remove all waste as fast as possible to prevent ammonia spikes.
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