How to Use Hot Tub Test Strips
To get an accurate reading of the water chemistry you should take a sample of water from as close to the middle of the tub as you can. Find a clean plastic or glass container, turn it upside down and dip it into the water about elbow deep. Then simply turn the container over and fill it up.
NB The reason you collect water from the middle of the tub is because you can get inaccurate readings by taking a sample near to the jets where the water can be overly aerated. Also, if you have an automatic chemical feeder (such as the spa frog system) there is likely to be higher levels of sanitiser near the jets.
Just dip a strip into the water and remove immediately. Do not shake excess water from the strip, hold horizontally for 15 seconds and compare the colours on the strip pads with the colour chart on the side of the bottle.
Store your test strips in a cool dry place and do not let them get damp.
The accuracy of the readings will deteriorate quickly after the use-by date printed on the pot, so always check that the test strips are in-date prior to use.