Nathan Hill explains how you can avoid some costly errors when undertaking this very important part of your fishkeeping routine.
Aquarium test kits are the most important part of our fishkeeping routine. They let us know exactly what’s going on with our water and save countless fish lives.
However, many fish keepers make a few simple errors when performing tests. These can affect both our wellbeing and that of our fish.
Safety first
Test kits often contain hazardous chemicals. Check to see if your labels include a skull and crossbones, or any other triangle warning.
You should always wear gloves and eye protection when handling these chemicals. Many retailers will glove and goggle up when doing a test.
Take care when shaking samples in tubes. Always ensure the lid is on before you start and never cap with your finger or thumb. Many hazardous chemicals permeate the skin and you don’t want them roaming your body.
Then there’s the tube itself. Handle test tubes firmly and gently, especially glass ones. They break incredibly easily and the last thing you want is a cut from a sharp edge laced with a chemical reagent.
Keep things clean
Inaccurate results can be caused by soiled test tubes. Rinse them between tests and clean and dry them before storage. Dried reagent from one test can play havoc on another, providing false readings when everything in the tank is fine.
You must clean the lids or caps, too. Many people remember to wash tubes, yet leave lids dirty.
Fill the test tubes correctly
Most kits offer clear instructions for use, but some are vague. When filling a test tube to a line, you want to fill to something called the bottom of the meniscus. This is a curve in the surface of the water that you’ll notice in a confined space — like a test tube! When measuring a liquid, always measure from the bottom of this curve, not the top where the fluid stretches up the glass.
One-way water
When taking a sample from a tank, try to use a pipette or syringe. In absence of these, if you put the test tube into the tank itself, never to spill any water back into the aquarium. If you take too much, pour it into the sink. Any reagent residue left in the tube could easily wash back into the tank and harm fish.
Hold bottles upright
Some test kit bottles will give a slightly different drop size if held at a 90° or 45° angle when used. Many kits require a full-sized droplet from a bottle held at 180°. Always ensure the bottle is totally upside down when counting out drops.
Check the date
Test kits begin oxidising from the moment you open them and then only have a finite lifespan.
Always check that water tests are in date to start with. Also, determine how long the kit lasts once you’ve opened it.
Many will only be good for around six months after first use. That two-year-old kit might be giving good readings in the fish tank because it is no longer working!
Finally, it’s important to shake all the bottles before use!
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