We live in a society that seems to be preoccupied with testing. Athletes are tested for illegal substances, would-be drivers are now tested for both theory and practice, and more recently, AS Level students have been reputedly tested to the limit and beyond. Furthermore, as research develops new testing techniques, there is an irresistible urge to make use of them. For example, ever since insurance companies recently discovered how our genes may reveal a certain disposition to specific hereditary diseases, they feel they must test our genes to discover more about their ‘risk’.

As aquarists or pondkeepers we too must utilise the technology that is available to us to determine the condition of our aquatic environment  and also to highlight any risk factors that we must respond to.

As water quality is at the heart of successful fishkeeping, (the majority of enquiries to the Nishikoi Information centre are water quality related) we can optimise our success and the health of our fish by maintaining a suitable water quality. But if we don’t measure it, how can we manage it?

1. Knowing what to test for.

2. Knowing when to test.

3. Knowing how to test.

4. Interpreting and acting on the results.

Water is a marvellous substance. It is essential for life and performs many different dynamic functions. It can adopt an unlimited number of characteristics, being shaped by its environment and in turn, affecting that same environment through its changing composition. Because of its seemingly endless capabilities as a solvent, water could in reality be tested for each of the myriad of compounds that can dissolve into it. This would make water testing impractical when trying to gauge a water’s suitability for fish.

Consequently, we tend to rely a great deal on the assumption that our water source is empirically suitable and non-toxic to fish such that we can limit our investigations to only a handful of tests. For example, we do not test our water for mercury, arsenic, cyanide etc as we do take our water to be safe. We do however, test for the more likely and influential factors that can affect our fishes’ environment on a regular basis. We could test our water each day for say, its gold content, but it would be unnecessary to do so as we know that gold levels are not likely to change and that gold does not influence our fishes’ health as much as other key characteristics. So what are the parameters that we should be testing?

There a over a dozen different test kits available, each testing for a specific water parameter. This could be daunting as it suggests that testing water is likely to be expensive, lengthy and requires a degree of chemistry. Do not be alarmed as there are essentially 3 key test kits that you should consider as these give you a useful snap shot of the health and risks in your pond or aquarium. Should you wish to delve deeper into the chemistry of your pond or aquarium, then you can also test for more diverse, but less critical parameters.

a. pH. This measures the acidity or alkalinity of your water and acts as a quick and useful guide to its suitability for fish. As fish originate from different habitats across the world, they each have their own desirable pH. If the pH is unsuitable, it will cause that species stress and lead to health problems. In order to make a judgement as to the suitability of your water, we need to know the pH requirements of your fish. Pond fish prefer a pH between 7.0 and 8.5 while marines require a steady 8.2 to 8.4. Amazonian fish require slightly acidic pH of less that 7.0.

b. Ammonia. Where the pH of water is tested prior to introducing fish (as well a checking that it is maintaining a satisfactory level) water is tested for ammonia during the maturation of a filter or while fish are being stocked. Ammonia is the toxic substance excreted by fish which must be broken down by bacteria in a filter. If it is not broken down faster than it is released, it will accumulate and cause the fish stress. Ammonia test kits are used to check that the filter is coping with the waste produced by fish.

c. Nitrite. The bacteria responsible for breaking down ammonia act quite quickly, converting it into nitrite which is still toxic and more persistent in an aquarium or pond. A different range of bacteria break nitrite down into relatively harmless nitrates, but can take a long time to do so. Consequently, nitrite tests should be used to ensure that the filter is mature enough to cope with the current stocking and feeding regime.

Water should be tested regularly for pH to ensure that it is maintained at the correct level. Water used in water changes should also be tested to determine that the pH is desirable. Ammonia and nitrite are tested very frequently during the running in of a new aquarium or pond. These tests will show how the filter is maturing and whether it is keeping pace with the rate at which waste is being produced. Once a pond or aquarium is fully stocked and has been running satisfactorily for several months, there should be little need to use ammonia or nitrite test kits.

All test kits or testing equipment are made with the fishkeeper in mind and are easy to use and interpret.

A. Colourmetric Test Kits. These rely on a chemical reaction between the water and a reagent which results in a colour change that can be compared against a colour chart.

i. Liquid. Drops of liquid reagent are added to a measured test sample of water and allowed to change.

ii. Tablet. Instead of drops of liquid, dry tablets are crushed and dissolved in the sample water and the colour change compared to a chart.

iii. Test Strips. Plastic strips, impregnated with reagent are dipped into the sample water and allowed to react, causing a colour change.

B. Electronic Tests. A range of pocket sized digital meters are available, giving a numerical reading. Digital meters are accurate and require regular calibration against known samples but are considerably more expensive than colourmetric tests.

The time and money spent on testing water would be wasted if the results were not acted upon. If having tested your water, you discover that the water quality is not as good as it could be, appropriate remedial action should be carried out immediately.

If pH is too low: Add some treated tap water (which is artificially buffered) or add a source of lime such as limestone chippings or crushed shell.

1.  Stop feeding

2.  Do not introduce any new fish

3.  Carry out a 20-30% water change

4.  Only start feeding when reading is back to zero (this may take a few days). Carry out a test each day for the next week.

However, if a positive ammonia reading reappears upon daily testing, carry out steps 1-4 again. As the filter matures, an ammonia reading is less likely to occur.

If you use other test kits, testing for other parameters (such as nitrate, Boron, Selenium, Silicates etc), then similar corrective action will be required if the results are undesirable. The more stable and mature the aquatic environment, the less the water will need testing, being able to use experience and the monitoring of fish behaviour as a quick way of assessing the quality of their environment. Nevertheless, when striving for better fish health, there is no substitute for providing good quality water with testing being the only definitive method of verifying its suitability for your fish.