How to test your aquarium's water, and what to look for.
Maintaining good water quality is the single most important component in sustaining a thriving aquarium. It sounds simple to do, but most hobbyists quickly discover that maintaining high water quality is one of the most challenging aspects of the hobby. Water can have a wide array of chemical and mineral characteristics, especially when it comes out of your tap. In a nut shell, water is a chemical compound, and chemistry is not a simple science!
The Basics of Water Chemistry
The term “water chemistry” refers to the chemical properties of the water in your tank. These properties may include pH, general hardness, carbonate hardness and ammonia, nitrite and nitrate levels. All of these properties vary depending on where you get the water you use to fill your tank and how you treat it beforehand (if you treat it at all).
Most aquarium hobbyists use tap water to fill their aquarium. Unfortunately, tap water contains elements that can be harmful to fish. To remove these harmful elements it is necessary to cycle your water using a biological filtration system. Cycling your water means to have your water go through a biological process called the Nitrogen Cycle. The Nitrogen Cycle establishes bacteria in your water and filtration system that is beneficial to the overall health of your fish. This cycle can take anywhere from two weeks to two months to complete. Once the cycle is complete, the harmful elements of your tap water will have been removed by the bacteria established during the cycle, thus giving you good water quality for keeping fish.
During the Nitrogen Cycle and regularly thereafter, it is essential to constantly test your water for pH, ammonia, nitrites, nitrates, general hardness and carbonate water hardness (alkalinity). The following list describes how to test for each of these water attributes and what the results mean in regards to your overall water quality.pHThe pH of water measures the acidity or base of your water. pH is very important in keeping healthy fish because high or low pH levels can stress fish and puts their overall health in jeopardy. The pH scale ranges from 0 to 14 with 0 being the absolute most acidic water can be and 14 being the absolute most basic your water can be. pH balance, or a neutral pH value, is 7. Most freshwater fish thrive when you have a pH level between 6.6 and 7.8. If, after conducting a pH test, you find the pH level to be unacceptable, you can raise or lower your pH levels by purchasing chemical products from your local pet store such as Aquarium Pharmaceuticals pH Up or pH Down. Maintaining a consistent pH level that is suitable to your fishes needs is the first step towards consistently high water quality.Ammonia
Ammonia is extremely toxic to fish and can quickly kill them. Unfortunately, it is naturally produced in all aquariums as waste and uneaten fish food breaks down. At no time do you want a reading of over 0ppm (part per million) in your tank. There are many products that can be bought at your pet supply store to break the ammonia down, but until your tank has completed the Nitrogen Cycle it will probably be present in small amounts in your tank. For this reason, it is imperative to only add very hardy fish such as Mollys during the beginning stages of the Nitrogen Cycle if you must add fish before the tank has cycled. Once the cycle has completed, ammonia will be broke down quickly by the good bacteria that is present in the tank.NitritesNitrites are the result of ammonia being broken down by bacteria in your tank – they are the secondary product of the Nitrogen Cycle. Though less harmful than ammonia, nitrite is still very toxic to tropical fish. In new tanks, these levels will rise very shortly after ammonia levels level off and being to drop. When you test for nitrates in your cycled tank, you ideally want a result of 0ppm. The only way to remove Nitrites from your tank is to perform weekly water changes (25% - 30%).NitratesNitrates are the result of Nitrites being broken down even further by the beneficial bacteria in your filtration system – the third and final product of the Nitrogen Cycle. Nitrates are not particularly harmful to fish and their presence signals the complete cycling of your tank. In very high levels, however, they too can become a stress on fish. Moreover, it is assumed that high nitrate levels can produce a biological bloom in your tank which produces very cloudy water. Nitrate levels should be between 20 and 40 ppm to remain in a safe range. To decrease the amount of nitrates in your tank, perform consistent water changes.General HardnessGeneral hardness is a measurement of the total dissolved minerals (calcium and magnesium) in your water. When your water has low amounts of dissolved minerals, it is considered soft. When it has higher amounts, it is considered hard. Soft water can cause pH crashes which can stress fish in your aquarium. The result of a water hardness test is measured in degrees (dH) and the type of fish and plants you have in your tank should dictate what the acceptable reading should be. For most community tanks a reading within 5 to 12 degrees should be acceptable. If your reading is too low, performing a water change should raise your general hardness level.Carbonate Hardness (Alkalinity)An alkalinity test determines your water’s ability to maintain pH - it is an indicator of how stable your water quality is. Low alkalinity levels mean that your pH will fluctuate more easily which can put stress on your fish. A low level also will stunt the growth of any live plants in the tank. For most community aquariums, a good alkalinity level should probably read between 7 and 12 degrees (dKH). Water changes can help increase alkalinity levels and there are products available at your local pet supply store that call also help raise alkalinity.
Buying a Testing Kit
In order to perform these water tests you will, of course, need to purchase an aquarium water test kit. You can find these test kits at your local pet store and you can also purchase them online. Aquarium test kits come in several different forms, though most master kits contain all of the items youll need in order to test for ph levels, ammonia, nitrites and nitrates and water hardness. Two recommended kits that are readily available at most pet supply stores are Aquarium Pharmaceuticals (API) Freshwater Master Test Kit and the Mardel Master Test Kit.The Mardel Master Test kit uses easy-to-use paper testing strips and can be purchased for around $30. The kit includes test for ph, hardness, alkalinity, ammonia, nitrites and nitrates. For more information on this kit, visit: