Your Trouble-Free Test Kit

Thank you for your purchase of a TF test kit! This guide will detail the different tests available in your kit and how your test results can affect your pool water. If you have further questions that are not covered by this guide, we encourage you to join Trouble Free Pool and pose your question on the forums, where our experts will quickly offer you personalized advice.

pH Comparator Block Test

pH measures acidity and basicity of your pool water. You should perform this quick and easy test every day using the R-0014 phenol red indicator and the TF comparator block. Interpretation of the colors is subjective, so this test is not intended to provide exact measurements for pH and chlorine.  However, since there is a wide range of acceptable pH (7.2 to 8.0) and chlorine levels (depends on CYA) you shouldn’t agonize over reading the comparator block.

pH levels below 7.2 can cause eye irritation for swimmers. pH levels below 6.8 can cause damage to metal pool parts, particularly heaters with copper coils. pH above 8.0 can lead to calcium scaling.

To raise pH add borax or soda ash. To lower pH add muriatic acid.

We recommend performing this test daily.

Many pools have a tendency to raise their pH over time. This is particularly true for fresh plaster that is less than 1 year old, or for pools with high total alkalinity (TA).

 

Chlorine Comparator Block Test

Chlorine is required to sanitize your pool water and avoid algae growth. This test is not intended to be highly accurate, as the interpretation of the colors on the comparative block is subjective. R-0600 only measures total chlorine (TC) as opposed to free chlorine (FC) and combined chloramines (CCs). However, it is extremely quick, inexpensive, and useful to tell whether you have chlorine in your pool or not. 

If you are not experiencing any acute pool water problems (i.e. algae) and expect a result of <5 ppm TC, use this test instead of the FAS-DPD chlorine test. It will save you time and money. Optimal FC levels depend on your cyanuric acid (CYA) level. See the chart below.

We recommend performing this test daily.

To increase FC, add liquid chlorine or non-additive bleach. FC will decrease over time at varying rates due to sunlight and sanitization.

Comparator Block Tests Instructions

1. Rinse the test block and fill both sides with pool water up to the thin black line about 1⁄4" from the top. Your fill level doesn’t have to be perfect.
2. Add 5 drops of R-0600 to the yellow side and 5 drops of R-0014 to the red side.
3. Cap both sides and shake for 5 seconds to mix.
4. Hold the test block at eye level. Match the colors of the solutions to the colors printed on the test block and record your pH (red side) and total chlorine (yellow side) results.

 

FAS-DPD Chlorine Test

Free chlorine (FC) is required to sanitize your pool water and prevent algae growth. Use this test if you need accurate and reliable results at FC levels greater than 5 ppm. There are two parts to this test: the first endpoint determines your FC level, and the second endpoint determines your combined chloramines (CCs) level. Combined chloramines indicate that your FC is actively sanitizing your pool, and they create the chlorine smell that many people associate with swimming pools.

Free chlorine (FC) + combined chloramines (CCs) = total chlorine (TC)

We recommend performing this test as needed. If you are experiencing an acute pool problem like algae growth or if you are unsure if you have a problem, use this test instead of the chlorine comparator block test.

If your CCs level is 1.0 ppm or greater, you should SLAM (Shock Level and Maintain) your swimming pool to restore sanitation. See page 10 for more information.

The FC/CYA Chart

The most critical fact of maintaining your pool water is that optimal FC levels depend on your CYA level. After performing the Cyanuric Acid (CYA) test included in your test kit (see page 7), use your CYA reading to find your optimal free chlorine (FC) levels below. If your pool has a saltwater generator, use the levels in the Saltwater Pool Optimal FC Levels column. If your pool is chlorinated with liquid chlorine or tabs, use the levels in the Non-Saltwater Optimal FC Levels column.

 

Green cells denote optimal CYA levels, red cells are not recommended as they are inefficient or do not sufficiently protect your FC.

If your pool is green and cloudy and/or your combined chloramines (CCs) level is >0.5 ppm, you should SLAM your pool using the process linked below.

FAS-DPD Chlorine Test Instructions

1. Rinse the “Chlorine Only” graduated cylinder with pool water.
2. Fill the “Chlorine Only” graduated cylinder with pool water to the 10 mL mark.
3. Using the small spoon shaped end of the dipper, add one scoop of R-0870 and swirl to mix. If the sample turns pink for a moment and then turns clear again, or if it turns brown, add another scoop of R-0870.

NOTE: If the sample remains clear the entire time, your FC level is probably zero. However, you must verify that with an OTO chlorine test, since the FAS-DPD test can give false zeros on rare occasions.

4. Swirling constantly and counting the number of drops as you go, add R-0871 one drop at a time. Continue adding drops until the color changes to clear. The pink color may become extremely faint before it goes away. Make sure that the sample goes completely clear.
5. Multiply the number of drops by 0.5 to get your FC level. Record your FC level.
6. Add 5 drops of R-0003 and swirl to mix. If the sample remains clear, your CC level is zero and the test is complete.
7. If the sample turns pink again, add R-0871 one drop at a time, swirling constantly and counting the number of drops as you go. Continue adding drops until the color changes to clear. The pink color may become extremely faint before it goes away. Make sure that the sample goes completely clear.
8. Multiply the number of drops by 0.5 to get your CC level. Record your CC level.
9. Dispose of the sample safely. It is best to pour it down the drain with the water running. Do not add it back to the pool.
10. Rinse the sample tube with tap water and store for next time.

 

Total Alkalinity (TA) Test

Total alkalinity (TA) measures your pool water’s ability to buffer, or resist, drastic pH changes. 

At low TA ( <50 ppm), your pH tends to fluctuate wildly. At high TA ( >90 ppm ) the pH will increase slowly over time.

To increase TA, add baking soda in small quantities and test your pH between each addition to ensure your pH does not exceed 8.0. To decrease TA, add muriatic acid to decrease your pH, then aerate your water.

We recommend performing this test weekly at first until you understand your pool water’s tendencies. Then, you can perform it monthly or twice monthly.

1. Rinse a graduated cylinder and fill to the 25 mL mark with pool water.
2. Add 2 drops of R-0007 and mix. Then, add 5 drops of R-0008 and mix again. Solution will turn green.
3. Add R-0009 one drop at a time, swirling between each drop. Wipe the tip of the bottle after every drop with a damp cloth to ensure consistent drop sizes. Continue until the color changes to red. 
4. Multiply the number of drops of R-0009 by 10 to yield your TA result in ppm. Record your TA result.

NOTE: In the presence of high chlorine, initial color after addition of R-0007 may be blue and shift to yellow at endpoint. However, the test is still valid if so.

 

Calcium Hardness (CH) Test 

Calcium hardness (CH) measures the amount of dissolved calcium in your pool water. The recommended range of CH varies based on your pool or spa’s construction.

Fiberglass-lined pools and plaster-lined pools should be kept between 250 and 650 ppm of CH. 

At low CH ( <250 ppm) your water will leach calcium out of your plaster, pebble, tile, stone, and sometimes fiberglass. High CH ( >650ppm) may cause equipment problems.

Vinyl-lined pools should be kept between 50 and 650 ppm of CH. High CH ( >650ppm) may cause equipment problems.

To increase CH, add calcium chloride or calcium chloride dihydrate, which are sold by hardware stores as “deicer” and by pool stores as “calcium increaser”. To decrease CH, replace some of the water in your pool with fill water that is reverse-osmosis treated or otherwise low in CH. 

We recommend performing this test weekly at first until you understand your pool water’s tendencies. Then, you can perform it monthly or twice monthly.

CH Test Instructions

1. Rinse a graduated cylinder and fill to the 10 mL mark with pool water.
2. Add 10 drops of R-0010 and mix. Then, add 3 drops of R-0011L and mix. Color change to red indicates the presence of calcium.
3. Add R-0012, one drop at a time and mixing between, until color changes to blue
4. Multiply the number of R-0012 drops by 25 to yield your CH result in ppm.  Record your CH result.

NOTE: If your pool water contains known copper, add two drops of R-0012 PRIOR to adding R-0011L and continue. Count the two drops in your R-0012 total. Record.

 

Cyanuric Acid (CYA) Test

Cyanuric acid (CYA), also called stabilizer or conditioner, protects your free chlorine (FC) from sunlight. The higher your CYA level, the more FC your pool needs in order to remain sanitary. Maintaining proper CYA levels allows you to efficiently protect your FC without requiring high levels of FC to sanitize your pool, which can be expensive to maintain.

Optimal CYA levels are 60 to 90 ppm if you have a saltwater chlorine generator (SWG), or 30 to 60 ppm if you do not.

To increase CYA, add granular or liquid CYA into your skimmer basket. To decrease CYA, replace some of the water in your pool.

One very common pool water chemistry problem that owners face is very high CYA from long-term Trichlor or chlorine puck/tablet use. To avoid this problem, we recommend using Trichlor pucks only if your CYA is low. Otherwise, you should chlorinate your pool only with liquid chlorine or a saltwater chlorine generator.

We recommend performing this test weekly at first until you understand your pool water’s tendencies. Then, you can perform it monthly or twice monthly.

Please note that this test can be subjective. For this reason we recommend watching a video tutorial of the test on our YouTube page by following this link.

CYA Test Instructions

1. If you have a TF-100 or TF-100 Salt test kit: Fill the red-capped CYA mixing bottle to the bottom of the white label with pool water. Now, fill the bottle to the top of the label with R-0013. Mix, then wait at least 30 seconds. Shake once more.

If you have a TF-Pro or TF-Pro Salt test kit: Fill the red-capped CYA mixing bottle to the 7.5mL mark with pool water. Then, fill to the 15mL mark with R-0013. Mix, then wait at least 30 seconds. Shake once more.

2. Hold the CYA View Tube at waist level, looking down into the tube, and slowly fill using the mixture in your CYA mixing bottle. Keep filling until the black dot in the bottom of the tube is completely obscured.  
3. Bring the tube back to eye level and note fill level of the view tube. CYA levels are always multiples of 10 - if your reading is halfway between two graduations, round up to the larger reading. Record your CYA level.

 

Salt Test

Salt is required for optimal operation of your saltwater chlorine generator (SWG). If you do not have a SWG, you do not need to maintain salt levels in your pool, although some owners report that saltwater “feels” subjectively better.

Optimal salt levels vary based on your saltwater chlorine generator, so consult your generator’s manual for the most accurate target level. Most generators run best with 2500 to 3500 ppm of salt.

To increase salt, add salt into your pool that is labeled solar salt, water softener salt, or pool salt. Avoid salt products that contain rust inhibitors or other additives and choose a product with 99.4% purity or above. Typically it is not necessary to decrease salt levels, but if you add too much for your generator to function, you will need to replace some of the water in your pool.

We recommend performing this test weekly at first until you understand your pool water’s tendencies. Then, you can perform it monthly or twice monthly.

Salt Test Instructions

1. Rinse and fill the plain graduated cylinder to 10 mL mark with water to be tested.
2. Add 1 drop of R-0630. Swirl to mix. Sample should turn yellow.
3. Add R-0718 dropwise, swirling and counting each drop, until color changes from yellow to a milky red.

NOTE: Do not add enough R-0718 to give a brown color. Once the color of the solution has changed from yellow to milky red, that is the endpoint of the test. 

4. Multiply the drops of R-0718 you added by 200 to yield your salt level in ppm.