How-To Guides | Using Test Strips - Get Accurate Results Every Time

To maintain safe spa water, you must be able to test the water and get accurate results. Long ago, people thought spa test strips were less precise than more complex liquid test kits.

With advances in technology, test strips have become the preferred testing method. They are cheaper and much easier to use than the old style liquid kits.

There's no equipment to clean. You never have to keep track of various chemical reagents... a drop of this, two drops of that. Hot tubbing is for fun and relaxation, so keep water testing as simple and easy as possible. This is not rocket science!

Why We Test Spa Water

Testing helps us balance hot tub water for both comfort and equipment protection. It also lets us maintain a spa sanitizer system. Both of these result in healthy, microbe free water.

Adjust Total Alkalinity (TA) first, and then look at pH. Correcting TA often brings pH in line. You can find complete instructions for water balance on our Prep & Maintenance page.

Simple Testing Procedure

When using a standard sanitizer like bromine, check spa water weekly. With a mineral based system like Nature 2, testing is only required twice a month. Note: Read the instructions on the bottle. Testing varies by test strip brand.

  • Allow spa to circulate for a minute or two. Then take a sample of spa water in a clean plastic drinking glass - a few ounces will do.
  • Remove a spa test strip from the bottle, and recap tightly.
  • Dip the strip in the water just deep enough to wet the test pad(s). Remove the strip according to bottle directions.
  • Remove excess water on the strip by giving it a quick shake (again, check the bottle directions).
  • Hold strip pad side up for 15 seconds (or per bottle instructions).
  • Compare colors on strip with bottle chart.
  • Adjust spa water as needed. See Prep & Maintenance instructions.
  • For best results, circulate water for a few hours or overnight after adding chemicals, then retest.

Watch your Fingers

Be sure to wash your hands before testing. Bromine, chlorine, or other residues on fingers can skew the test results. Never put a wet finger into the test strip container. This will contaminate the unused strips.

Store Strips Properly

Don't store your test strips outside. Keep them at room temperature, dry, and away from direct sunlight. Cap the bottle tightly right after removing a strip - don't wait until you are done testing.

Use Fresh Strips

Check the date on the bottle and replace expired strips.  Old strips may give false readings, leading to improper water balance.

For Chlorine & Bromine Users Only

When buying test strips, make sure they measure Total Bromine and/or Total Chlorine. Not all brands of test strips do. Total bromine/chlorine is the sum of free chlorine/bromine and combined chlorine/bromine. Our test strips test for total.

Bromine Testing - Free bromine is the most active form of the sanitizer. When it reacts with pollutants, it becomes combined bromine.

Combined bromine is still about 80% effective. Convert it back to bromine using shock, such as OxySpa. You need test strips that test Total Bromine.

Strips that only test free bromine can falsely show the need to add bromine. Often, there is plenty of combined bromine still present in the water.

Chlorine Testing - Chlorine testing is a different story. Only free chlorine (the form of chlorine you add to the water) is a good sanitizer.

When free chlorine reacts with contaminants, it becomes combined chlorine, but then has little sanitizing ability. Combined chlorine can irritate skin, and has a strong odor.

Get test strips that measure both free and total chlorine, so you know the amount of combined chlorine present.


[Total Chlorine] - [Free Chlorine] = [Combined Chlorine]


Our wide variety of test strips are the best quality, most accurate water tests money can buy!

AquaChek Test Strips

"I would just like to say that I got the best customer service in a long time. Tech Support was great, they helped me choose the right test strips, which were a great buy. I got the right balancing chemicals and they didn't try to sell me stuff I didn’t need."

Trace Ives
Boulder, CO

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