Kordon AquaTru Water Quality Test Kits pioneered the use of dry reagents for use in aquarium and pond water testing using colorimetric water test kits. The major advantage of dry reagents is in their accuracy and shelf life. AquaTru Dry reagents for water testing are more stable than colorimetric tests done with test strips or liquid reagents.  This means that the aquarist and pond keeper can perform tests using Kordon AquaTru water tests with the confidence of knowing the results will be as accurate as is possible for a "colorimetric" type test.  Also, Kordon dates their reagents with their expiration dates.  All manufacturer's reagents, whether dry or liquid, are subject to degradation. Because the reagent chemicals break down over time, it is important to know when the reagents are going to go out of date.  Therefore, it is not recommended to use reagents that are not dated to show when they are out of date. 

AquaTru's color comparator system has been carefully designed to reflect the needs of the concerned aquarist and pond keeper. The top is flared to make adding reagents easier,.  The wide base increases stability.  A special sliding window helps make color comparisons more accurate. The color strip consists of translucent colors applied to a durable plastic, rather than a printed paper card. The translucent color strip allows light to pass through, providing a much more accurate match when comparing the cube's colors to those produced by the reagents. Reflected colors, such as those produced on a printed comparator do not match as well when compared with the translucent colors in a test cube.

The quality of tap water varies widely and aquarium and pond systems.  It is increasingly important to monitor water conditions carefully in the aquarium and pond. It is equally important to select only top quality, reliable test equipment to monitor these conditions. It is beyond the scope of most aquarists and pond keepers to analyze the accuracy of a test kit. They must depend upon the manufacturer to provide them with accurate, dependable test kits.  Kordon has provided professional quality accurate water quality test kits in its AquaTru products for over 30 year, which are of the same grade as provided to scientific laboratories, government agencies, academia, and to commercial aquaculture. 

STABILITY OF REAGENTS AND  COMPARATOR STANDARD COLORS
The reagents should be used before the expiration date shown on the package. If the reagents are to be used after the expiration date they should be checked with an accurate standard solution to insure the reliability of the reagents. Otherwise, the reagents should be replaced.  The reagents should be stored in a cool place. If the Aqua-Tru reagents go out of date, send them back to Kordon and they will be replaced free.  The color comparator strip should not be exposed to strong light sources for an extended length of time to prevent fading of the colors.

 PRODUCT INFORMATION ON COMPATIBLE PRODUCTS
All of Kordon's products are compatible with the Kordon's Aqua-Tru Water Test Kits.  In particular, it is recommended to use Kordon's AmQuel+ to eliminate chlorines and chloramines (combinations of ammonia/chlorine) from the water, as well as all ammonia/ammonium, nitrites, nitrates, and other toxic nitrogen compounds for which there are no common names.  AmQuel+ irreversibly has to remove per dose the amounts of these compounds shown on the product label and in its description (see product description for AmQuel+). 

CHOOSING WHICH pH TEST KIT TO USE
For a community aquarium with different kinds of freshwater fishes, the AquaTru freshwater Low Range pH Test Kit to test the acidity/basicity of the water is usually the best to use, seeking a pH range for the fishes between 7.0 and 7.5.  For specialized fishes in fresh water, such as African Rift Lake Cichlids, and low salinity brackish-water fishes, the  freshwater High Range pH Test Kit is usually the best to use, because the pH range to seek is going to be 7.5 or higher..  For all marine and coral reef fishes and aquatic invertebrates the Marine pH Test Kit is the proper one to use, with normally the pH range being sought is 8.2-8.3.  

CHOOSING WHICH AMMONIA TEST KIT TO USE
It is recommended to use either the freshwater or saltwater AquaTru Salicylate Ammonia Test Kit, because they are low-range tests.  the water should be kept for fishes at or below 0.25 ppm (= 0.25 mg/L) ammonia, and for some fishes as low as at or below 0.05 ppm.  The Salicylate test kit was developed in order to test the water in the right range from 0.0 to 0.8 ppm (= 0.0-0.8 mg/L) in salt water, and 0.0 to 1.0 ppm (0.0 to 1.0 mg/L in fresh water.

The Nessler reagent was the first of the ammonia colorimetric tests invented for testing ammonia in water.  It was originally developed for use with shellfish seafood (lobsters, crabs, shrimp, mollusks) that have a higher tolerance above 1.0 ppm (=1.0 mg/L) for ammonia than do fishes.  The Nessler test is a high-range ammonia test and is not useful in reading the lower ammonia readings required for fishes, as well as for many of the aquatic invertebrates kept in freshwater and marine aquariums.  Therefore, the AquaTru Nessler Ammonia Test Kit is for special uses, mainly for invertebrates that tolerate higher levels of ammonia in the water, and is not recommended for use in fish keeping and in general aquarium and pond testing. 

CHOOSING WHICH NITRITE TEST KIT TO USE
Nitrites at any level are toxic to fishes and should be eliminated.  0.1-0.2 ppm (0.1-0.2 mg/L) nitrites or less is what is needed at the highest in the water for aquarium and pond keeping.  Preferably the nitrite level should be kept at a zero reading on the AquaTru Nitrite Test Kit, which is for either fresh or salt water aquarium and pond conditions. 

CHOOSING WHICH NITRATE TEST KIT TO USE
Both fresh and salt water should be kept at or below 10 ppm (= 10 mg/L) nitrates in the water for most fishes.  Aquatic invertebrates have higher tolerances to nitrates, the level depending upon which group of invertebrates are being considered.  Therefore, for fish keeping the AquaTru Low Range Nitrate Test Kit should be used.  The AquaTru High Range Nitrate Test Kit mainly reads from 35-175 ppm (= 35-175 mg/L) and is for special purposes, such as for coral reef aquariums with invertebrates that tolerate the higher levels of nitrates.  However, in general aquarium and pond keeping, the nitrate level at or below 10 ppm will provide safer water conditions.  For this low reading the AquaTru Low Range Nitrate Test Kit needs to be the choice.

The most difficult colorimetric test kits to read in differentiating the shades of colors of the readings are the nitrite and especially the nitrate test kit. Care needs to be taken in deciding on their readings.  This is particularly true for less expensive and less accurate paper strip and liquid reagent water tests for nitrates and nitrites, for which there can be considerably different readings than for the accurate powder reagents.  .

RELATED KORDON ARTICLES
It is recommended to go to the Kordon Articles on the Kordon home page: to see further information about water quality test kits.  Particularly see the list of articles under the heading WATER QUALITY TEST KITS,  One of the useful articles is : Insights into Water Quality Test Kits