Which Test Kits are Needed for the Basic Aquarist?

Posted in All About the Water

I go into much more detail in What Test Results are Suitable for Oscar Fish?, but these are the kits I deem absolutely essential to every aquarist: 

  • Thermometer - Not a test kit, but it gives you vital information about your water. I prefer a glass thermometer with an expanding liquid over the chemical-based strips that stick on the side of the tank. IMO, the glass thermometers are more accurate. If you want to get fancy, you can get a calibrated lab thermometer (or even a digital thermometer) from a lab supply company, but IMO, this is going a little overboard for the average aquarist.
  • Ammonia (NH4) - Chose a salicylate reagent (2 part) kit over a Nessler reagent (1 part) kit.
  • Nitrite (NO2-N)
  • Nitrate (NO3-N)
  • pH - Get a kit or kits that cover at least from 5.0 to 9.0. Digital meters are available, and are nice, but not necessary.
  • KH (CaCO3)

How can I tell if my test kit has expired?

This information is from Aquarium Pharmaceuticals (the write-up below was authored by G). I would assume that kits using similar reagents would have similar shelf lives, but if you use a different brand it would be a good idea to check with the manufacturer.

Test Solutions Shelf Life from bottling date: 

  • Wide Range pH - 3 years
  • Ammonia #1 - 3 years
  • Ammonia #2 - 3 years
  • High Range pH - 3 years
  • Nitrate #1 - 3 years
  • Nitrate #2 - 3 years
  • GH - 3 years
  • KH - 4 years
  • Nitrite - 4 years 

To determine bottling date check the lot # on the reagent bottle. The last 4 digits are the month and year of bottling.

Example: 33A1209 would = a bottling date of December 2009.

What is the best way to read test results?

Again, this information is from Aquarium Pharmaceuticals (as submitted by Kmuda), but is probably accurate for kits from other manufacturers. Again, it wouldn't hurt to check if you use a different brand. 

When reading test results, it is best to place the test tube up against the white part of the color charts that come with the kits (not holding it away from the card, it should be touching the card). The colors on the cards are calibrated assuming you will do this. 

What procedures should I follow to ensure that my results are accurate?

  1. Make sure your test kit is fresh (see above).
  2. Make sure your testing equipment (tubes, caps, etc) is clean. I rinse mine thoroughly in tap water after each use, and occasionally wash them with water and a mild soap. If you use soap, make sure to rinse everything thoroughly to remove any remaining soap.
  3. Make sure that you have the correct amount of water/test reagents in your sample, check the instructions that came with your kit. Most of the time, water level is read from the bottom of the meniscus (the curved surface of water in the test tube).
  4. Sample before you do a water change or other maintenance. This gives you a good idea of whether your maintenance routine is adequate, and shows any problems that might be arising during normal tank operation. If you want to test afterwords (to confirm that parameters are still under control), wait at least a few hours to ensure thorough mixing, and settling of any suspended solids.
  5. Sample from the middle of the tank. You might get slightly different readings (especially for dissolved gases like chlorine, oxygen, carbon dioxide, and ammonia) if you are too close to the top or bottom of the tank. The middle strata will give you the best picture of the average condition of the water.
    Additional Tips:
  • Try to set aside one tube only for ammonia testing. False ammonia readings can occur if residue from prior tests (from different test kits) remains in the tube.
  • If you allow a test to sit in a tube for too long, the test kit will become stained with the color of the prior test. This stain can usually be removed by simply boiling the tube.
  • When using the API NO3 (Nitrate) test it is essential that you follow the instructions to the letter, or you will likely get a inaccurate reading. Put in your 10 drops of regeant 1, Shake shake shake, reagent 2 for 30 seconds, add the 10 drops of regeant 2 to the test tube, shake the test-tube for 1min and then wait the full 5 min.

 - Submitted by Saluki, updated by Kmuda