This is just a collection of my own tips for getting more consistent tests when using Hanna testing kits (the “egg testers” as some people refer to them). Others may have their own tips or variations on these but this is what works for me.
Environment
- Don’t test when in an extremely bright space or space that has inconsistent lighting like a window with bright light beaming in and shining on where you are testing. For example bright morning light shining direct on the tester will almost always skew the results for me.
- Have a flat clear surface available for the testers. When the tester is doing its thing just leave it flat on the surface – don’t walk around with it or continue to shake it.
- If the battery is getting low – just change it.
Reagents
- Check the expiry dates. I have had instances where I’ve seen enough of a difference with results between in-date and expired reagents that it’s not worth wasting time/money with out-of-date reagents.
- Shake the satchet reagent to one corner and break the powder before cutting open the sachet.
Vials
- Take a moment to rinse the vials before use. Just squirt some tank water into them, shake and empty – repeat a couple times. This is particularly important if testing multiple tanks. It’s also a good opportunity to rinse the sample syringe by filling and squirting into the vials.
- When filling, put with the vial on a flat surface and measure to the bottom of the meniscus.
Testing
- Turn the tester on with the lid shut and no vial.
- Make sure the test lid is fully shut – you might have re-screw the lid on the vial if it is sitting a little high.
- When zero-ing if it takes longer than 5 or so flashes to stabilize and ask for C2 – just start again. I have had way too many instances where I’ve continued when it takes 15+ flashes and the results are almost always not what I would expect and I need to re-test – wasting my time and the reagent/s.
- Remove bubbles / air pockets before zero-ing and performing the tests. I just slowly rotate the vials while horizontal to get them out.
- After testing I rinse the vials and syringes – I just use tap water (the water here isn’t that bad and its a week between when I test usually so everything dries out between testing).