freshwater community4


How To Modify Water Chemistry In A Freshwater Aquarium

In order to keep your aquarium water quality high, and the fish in your tank healthy, it is important to understand basic water chemistry and how to manipulate it if the need arises. In this article, you'll learn practical tips for maintaining happy, healthy fish.


cichlid xs 8644276To keep the water quality in your tank high, and the fish in your tank healthy, you should not only know what water chemistry is, but you should also learn how to manipulate it. It is not enough to understand that pH is simply a measure of how acidic or alkaline the water in your tank is – you need to know how to alter it if it becomes necessary. While pH is one of the most important aspects of water chemistry, it is not the only one. Elements that are also included are water hardness, buffering capacity, salinity and electrolytes. If you have a basic understanding of the principles of water chemistry, and how to alter it, you'll be better equipped to make changes to your tank when necessary. Quick action on your part can mean the difference between a drop in pH being quickly remedied or killing all the fish in your tank.

How to Test Water Chemistry

ph test xs 15020007Testing water chemistry is actually very easy – all you need is an aquarium water test kit. These kits can be found at your local pet store or they can be ordered online. Aquarium water test kits come in two varieties – some include test strips which can be dipped into a cup of tank water for testing and some include test tubes to which drops of a test solution are added. Once the water itself has been tested, the color of the test strip or sample can be compared to the chart included with the kit. These kits can measure several aspects of water chemistry, including pH and water hardness, as well as the presence of certain toxins and chemicals like ammonia, nitrites, and nitrates. In order to monitor the water chemistry in your tank properly, you should perform water tests on a weekly basis and record the results in a journal to keep track of any changes.

How to Alter Water Chemistry

baking soda xs 15821195Raising pH – PH is a measure of how acidic or alkaline the water in your aquarium is and it is measured on a scale from 0 to 14. Water having a reading of 7.0 is considered neutral while readings below 7.0 are acidic and above 7.0 are alkaline. There are a variety of ways to increase the pH in your tank, but some of the most popular ways are adding baking soda, Epsom salt, or calcium chloride. To raise pH, try dissolving 1 teaspoon of baking soda (NaHCO3) in 10 gallons of water. If you need to increase both the pH and KH (water hardness) in your tank, try using a mixture containing equal parts baking soda, Epsom salt and marine salt (calcium chloride). Use about 1 teaspoon of the mixture per 5 gallons of water. There are also commercial alkaline buffers made specifically for the aquarium hobby that will accomplish this goal.

Lowering pH – Lowering the pH in a freshwater tank can be tricky unless you are also able to buffer the water to the lower pH value. The buffering capacity of aquarium water refers to the ability of tank water to maintain a stable pH. If your tank water has a low buffering capacity while you try lowering the pH, it could result in an unstable pH which could harm or kill your fish. In order to first buffer the water, you must lower the alkalinity by using a source of naturally soft water such as rainwater or melted snow. Once you have lowered the alkalinity in your tank, you can then lower the pH using either peat moss or CO2 injection. Peat moss releases tannins into the water which will increase the acidity and lower the pH but it will also stain the water. Using a CO2 injector can be both tricky and expensive. This method is particularly dangerous because it will lower the pH in your tank without lowering the acidity so as soon as you stop the CO2 injections, the pH will increase rapidly as the CO2 leaves the water. A simpler way is to use a commercial acid buffer manufactured specifically for aquarium use.

reverse-osmosis-unitSoftening Water – To soften aquarium water simply means to lower the alkalinity. Soft water typically measures between 0°dH and 3.36°dH on the general hardness scale. In order to achieve a measurement this low it is best to start with water that is naturally soft. Rainwater, melted snow and water treated through reverse osmosis are all viable sources of soft water. If none of these options is available to you, you may need to purchase a reverse osmosis unit. These units can be very expensive, but if the alternative is to continue buying large quantities of R/O water, it may be the more financially sensible option.

Hardening Water – Increasing water hardness is much easier than decreasing it. On the scale of water hardness, moderately hard water measures between 3.42° and 6.72°dH and hard water measures between 6.78° and 10.08°dH. To harden water, simply add 1 teaspoon of Epsom salt per 10 gallons of water. You may also choose to add some calcium carbonate or marine salt to increase the calcium contribution to water hardness. Another way to increase the hardness of the water in your tank is to utilize calcitic gravel as a substrate – beware when using this technique, however, because it can raise the pH in your tank as well. Calcitic gravel can raise the pH in your tank up to 7.5 and it will also help to increase the buffering capacity of the tank water.

Electrolytes – The amount of sodium, one of the essential electrolytes in a freshwater tank, can be modified by adding one tablespoon of salt per five gallons of tank water. There are also some commercial products available that can be used to balance electrolytes in the home aquarium. These products are often marketed as buffers and may contain essential elements such as calcium, magnesium, sodium, potassium and iron. Another popular product is the mineral block which dissolves slowly over time, releasing small amounts of electrolytes of a sustained period of time.

Tips for Monitoring and Maintaining Water Chemistry

While you may be able to find chemical treatments for raising or lowering pH, these treatments are generally not recommended. Adding chemicals to your tank should always be considered a last resort because of the possibility of adverse effects on the fish. Some chemical treatments can also have adverse effects on your tank. PH-lowering chemicals such as sodium biphosphate, for example, can provide nutrition for algae-since phosphate is a "food source" for algae. Thus, using this product in your tank may solve your problems with high pH, but it could be in exchange for a new problem with excess algae growth. If you do decide to use a chemical treatment, look for one that does not contain sodium biphosphate.

Regardless which method you select to alter the water chemistry in your tank, it is very important to test the water before, during and after the treatment. Testing the water before you begin treatment will give you a point of reference in order to gauge any changes that occur. It is also essential that you monitor the water chemistry during treatment to ensure that changes are not made too quickly and that the changes do not end up being too extreme. Extreme or rapid changes in water chemistry can put undue stress on your fish. Species that are not adaptable to sudden changes in water chemistry could be killed. In general, you don't want to have more than a 2 point change in pH within a 24 hour period. For example, if the desired pH reading is 7.5 and the current reading is 7.0, then you should attempt to get the pH no higher than 7.2 within 24 hours. The operative word here is "attempt" since trying to hit a specific pH target is tricky at best. Depending on the general hardness of the water in your area, a simple 10-20% water change may be enough to accomplish the goal. Once you have completed the treatment, you should test the aquarium water chemistry to ensure that the levels are appropriate and check again within 24 hours to ensure that they have remained stable.

blog comments powered by Disqus