How to Test Aquarium Water: Strips vs Liquid Kits and a Weekly Routine (Part 4 of 4)

Mayur Dev|October 11, 2026

Testing is only useful if you know what to do with the numbers. Learn when to use test strips and when to use liquid kits, how to read a strip properly, how often to test, and exactly what to do with every result. Part 4 of our Water Parameter Series.

You now know which numbers matter and what they should read. The last piece is the habit that ties it all together: testing regularly and knowing exactly what to do with the result. This is Part 4, the final part of our Water Parameter Series.

Test Strips vs Liquid Kits: An Honest Comparison

	Test strips	Liquid reagent kits
Speed	Fast, results in under a minute	Slower, several steps per test
Ease	Very beginner-friendly	Needs care and timing
Precision	Good for trends and routine checks	More precise for borderline readings
Best for	Weekly routine checks	Confirming a result during cycling or a problem

For most hobbyists, strips are the right tool for routine monitoring. If a strip reading looks borderline, especially for ammonia or nitrite, confirm it with a liquid test.

How to Use Test Strips Properly

Dry your hands. Wet fingers can transfer water to the pads.
Check the expiry date, and store the tube tightly sealed and dry.
Dip the strip for the time printed on your TCWS Water Test Strips pack, then remove it.
Hold it flat and read the colours within the time window on the pack.
Compare against the chart in daylight, not under coloured aquarium light.
Log the result with the date.

How Often Should You Test?

Tank stage	Frequency
New tank (cycling)	Every 1 to 2 days
Fish-in cycling	Daily
Established tank	Once a week
After adding fish, medication or a big water change	Within 24 hours
Any time fish look unwell	Immediately

Read the Result, Take the Action

Reading	What it means	What to do
Ammonia above 0	Cycle incomplete, overfeeding or dead matter	Do a 25 to 30 per cent water change, dose Good Bacteria, feed less
Nitrite above 0	Cycle still developing or disrupted	Same as above, and test daily
Nitrate above 40 ppm	Waste is accumulating	Change 30 to 50 per cent of the water, review feeding and stocking
pH shifts by more than 0.5 in a day	Low KH, CO2 or hardscape effect	Test KH, do a partial water change, buffer slowly
KH below 3 dKH	Buffer is running out	Change water and add buffering gradually
GH out of range for your species	Water and fish are mismatched	Adjust gradually or choose better-suited fish
Temperature outside 24 to 28 C	Heater or room temperature problem	Check the heater and correct gradually

Your Weekly 10-Minute Routine

Test with TCWS strips and log the readings.
Do a 20 to 30 per cent water change if nitrate is climbing, using water treated with Sunken Garden Anti-Chlorine.
Check temperature and filter flow.
Look at your fish. Behaviour often shows a problem before a test does.

If you are still cycling a new tank, follow our four-part Nitrogen Cycle series. If your water turns cloudy, read how to fix cloudy aquarium water.