It's Time to Test the Waters!
The following is the fourth in a series of articles covering the basics of keeping freshwater tropical fish. These articles are designed with the beginner in mind, Although there certainly may be some good information in this series for more experienced hobbyists as well. If you are considering entering one of the most popular hobbies in the United States, and have never kept live fish before (or if you have just have had problems keeping your fish alive), then this series is written for you!
Last month we covered types of substrates and an easy (or so I hope!) explanation of the nitrogen cycle. If you haven't read the previous articles, look at the links at the top of this page and click to read them first.
This month's topic is testing our waters, a description of what each of the tests actually test for, and why we test. I will not be going too much into specific test equipment or how to use them since there are so many different types form different manufactures. It is always best to read the directions that come with the test kits themselves.
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Why test the water? |
Establishing and maintaining a healthy aquarium is essential for your fish's well being. To make sure that the aquarium is healthy, we check certain parameters that exist within the water. Things we can not see, but our fish feel. Sort of like if you walk into a room full of carbon dioxide (gas), you can not see it, but your body reacts to its effects. The same idea is with our fish and the environment we provide for them. Besides just maintaining a healthy aquarium, some of these tests can also help us when our fish seem ill or out of the ordinary.
Now last month we talked about the “Cycle” and the many chemicals compounds involved in it from ammonia to nitrites. If you have not read that article yet, I recommend you do so before proceeding on with the rest of this article since some terms and references may not make sense until you have read the previous articles.
I am going to list the tests in order that I personally feel are the most important first, and least important or relevant last. These are just my own personal views and you can certainly feel free to differ with me.
pH:
pH is probably the most important and most basic test for any hobbyist from the person with the 1-gallon fish bowl to the 125-gallon reef tank. Remember all the way back in article 1, when I mentioned even before buying any equipment or fish to have your pH tested, well here is the reason why a bit more in depth.
The term pH stands for the Power of Hydrogen and is simply a measure of hydrogen ions that are present in your water. pH is important and responsible for controlling many chemical balances in your water including the ratio of nontoxic ammonium (NH4+) to toxic ammonia (NH3) and between the nitrite ion (NO2-) and nitrous acid (HNO2). The pH scale runs from 0.0 to 14.0, but for the aquarium enthusiast generally we only deal with ranges between 6.0 and 9.0. Now you noticed the range is from 0 to 14, makes 7.0 half way in between, this is referred to as neutral. Everything below 7.0 is termed Acidic, and values above 7.0 are known as Basic or Alkaline.
Now fish have specific ranges that they can be kept in successfully, some species like the White Cloud Mountain Minnow can take a wide varied range in pH from acidic to basic. Other species like the more sensitive Discus can only take acidic water, anything other than that and stress is brought on.
It is always good to first check your source waters pH prior to purchasing your first fish, then research and purchase only compatible fish with in that pH range. By avoiding mixing high pH and low pH fish, it can save you a lot of grief as well as money.
Ammonia:
As I pointed out in last month's article, fish waste matter (fecal and urinary output) is converted by bacterium in your aquarium into ammonia. Ammonia itself exists in the water in two forms, toxic ammonia (NH3) and nontoxic ammonium ion (NH4+). At any given time, the amounts present in either form primarily dependent on pH, filtration and somewhat on temperature. Ammonia is more toxic at higher temperatures/high pH than it is at low pH lower temperatures. This is NOT to say if you have an ammonia problem to lower the temperature and pH of your water. There are other ways to treat for excessive ammonia, which will be covered in next month's article on chemical/natural additives.
The majority of test kits test ammonia as total ammonia, which is simply the combination of ammonia and ammonium together. To properly determine the true amount of ammonia check with your test kit for a conversion chart where it takes the reading of the test and converts it by using the current waters pH and temperature.
Now I know not everyone is going to run out and get a complete test kit, but if you have ever had problems with milky white or cloudy water, you really need to invest a little bit of money and get a decent complete test kit.
Nitrite:
Nitrite (NO3) is the produced from the ammonia by Nitrosomonas bacteria, the second part of the previously discussed “Cycle”. Nitrite is extremely toxic to fish because it interferes with the fishes ability to utilize oxygen. Nitrite is also pH dependent. If nitrite is present in your tank and the pH falls below 6.5 the nitrite will convert into nitrous acid. Nitrous acid is extremely harmful to fish as well as humans. If nitrite levels are present in your water in excess of 1.00 ppm (parts per million) it is highly recommended you do some immediate water changes of no less than 25% of total tank water volume with fresh water. As well as reducing feedings, and/or adding nitrite absorbing pillows/chemicals to your tank.
Nitrate:
Now some tests do not test for separate nitrate and nitrite amounts but simply combine the two, if at all possible get a test kit that does differentiate the two tests. Nitrate is the last and third part of the nitrogen “cycle”. Plants and algae use nitrates as food, hence those of your with abnormally high growth levels of algae would be benefited by having a nitrate test kit handy. For most freshwater aquariums nitrate levels should be kept under 60 ppm, however levels upwards of 100 ppm are usually tolerated. Anything above 100 ppm and again, frequent water changes of at least 25% total tank volume would be in order. NOTE: Saltwater/Marine setups should never exceed 20 ppm and reef tanks should not have any nitrates present.
If nitrates are a constant problem, live plants are an easy and possible solution to the problem.
Alkalinity:
Alkalinity or pH stability, is the measure of the buffering capacity of water, which is the ability to maintain a constant pH over an extended period of time. Alkalinity can vary depending on water source and environment. Water can come form limestone rich sources which have high mineral content can have an alkalinity of greater than 200 ppm. Fish like Rift lake Cichlids and brackish fish can come from waters with an excess of 80 ppm. Water, which comes from areas rich in granite and sandstone, has low mineral content and an alkalinity of less than 40 ppm. South American Cichlids such as Angelfish and Discus come from low alkalinity water. It is important not to intermix two species form opposite ranges, since these species will also generally be at opposite ends of the pH range as well. High alkalinity water usually has a pH of between 7.4 to 8.4 and low alkalinity water usually has a pH of 6.4-6.8 or lower. Water with low alkalinity will cause a steady drop in pH, into a range that is dangerously unhealthy for most fish.
Now here is where it all comes together, When you rapidly raise the pH with baking soda / pH up chemicals or a water change, the nontoxic ammonium will be converted to the more toxic ammonia. This causes stress on your fish, lowering the fish's immune system bringing on disease, other health risks or loss. It is important to test both the pH and the alkalinity on a regular basis because, if ammonia is present, any adjustments made to the water can greatly increase the ammonite of toxic ammonia in your water.
To reduce alkalinity in your water you can perform your water changes with distilled deionized or R/O (Reverse Osmosis) filtered water until the desired levels are obtained.
Hardness:
Hardness is broken down into two subgroups, Calcium hardness and magnesium hardness. Total Hardness is simply the sum of these two combined. Most test kits test for total hardness. As a general rule of thumb, in freshwater aquariums calcium hardness makes up about 70-90% of total hardness and magnesium hardness makes up the remaining 10-30%. Test results are usually expressed as grains of calcium carbonate and is measured as ppm or dH (Degrees of Hardness). To convert ppm to dH you simply divide the ppm reading by 17.1 (1 dH = 17.1 ppm). Generally most freshwater tanks should be in the range of 50-150 ppm (3-9 dH). Like alkalinity, to reduce the hardness of your water if needed can be achieved by simple water changes with distilled, deionized or R/O water.
Chlorine:
Most of today's supplied water systems add chlorine as well as other chemicals to the water before it comes out of your tap. Chlorine is very deadly to fish in heavy concentrations. You can either treat with chemicals (discussed in next month's issue) or simply leave the water exposed to air for 3 or so days prior to adding to your tank.
Specific Gravity:
For those of you who tend to add salt to their water for one reason or another, knowing how much salt is essential, especially for you brackish and marine keepers. A very simple and inexpensive test device for S.G. (specific Gravity) is called a hydrometer. A hydrometer simply measures the difference between your water density and that of when the test unit was calibrated with distilled water. Readings will generally range from 1.000 to 1.030. Freshwater tanks should be kept in the range of 1.000 to 1.004, brackish tanks from 1.005 to 1.020 and marine tanks from 1.017 to 1.026. Now these numbers are not absolutes but just general references. Now since you have no idea how mach salt is already in your tap or source water, blindly adding additional salts can be dangerous. Simply guessing the salt content of your water by adding a certain amount of teaspoons or tablespoons of salt per gallon can be like playing Russian roulette with your fish.
See you next issue when we discuss what to do when we find chemical imbalances, and how to treat them both chemically and naturally. Also we will go over “Green Water” since there has been such a demand for further information on this topic.
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