Pool Cert Flash 5. Chemical Tests

Question 1

What factors must be met to ensure all tests are performed to the most accurate standard?

Answer 1

1. Follow manufacturer’s instructions. 2. Testing eqt. must be clean. 3. Reagents less than 1 year old and supplied by manufacturer of the tests. 4. Reagents and Colorimeter should be kept away from direct sunlight and intense heat.

Question 2

Where should you gather your water sample to ensure a proper representation of the pool water?

Answer 2

The side is okay, but must not be by a pool inlet from the filters.

Question 3

Why are OTO (ortho-tolidine) tests not allowed as replacements for DPD tests?

Answer 3

Time factores, interfering substances, and turbid water can produce inaccureate chlorine test results.

Question 4

What must Bromine residual levels be held between?

Answer 4

2.0 and 8.0 ppm

Question 5

If water level exceeds 85 degrees F, what is the minimum level free chlorine and bromine residuals must be held at?

Answer 5

2.0 and 4.0 ppm

Question 6

What is the temperature range that indoor pools must be held between?

Answer 6

76 and 92 degrees F.

Question 7

What is turbidity?

Answer 7

The degree to which suspended particles in pool water obscure visibility.

Question 8

What is the ideal cyanuric acid level between?

Answer 8

25 and 50 ppm.

Question 9

What must the pH level in the pool be between?

Answer 9

7.2 and 7.6

Question 10

The DPD Chlorine Test indicates there is no chlorine in the pool, but the chlorinator is on and operating. Why does this happen?

Answer 10

Usu. an indication of too much chlorine in water, causes DPD to bleach out. Repeat test with diluted sample (fill half of vial with pool water, half with distilled). For a 1 to 1 dilution, multiply by appropriate factor (2). For a 1:2 dilution, multiply by (3).

Question 11

The DPD chlorine test sample turns cloudy when the first reagent is added. Will the test work?

Answer 11

Yes. Sample clouds usu. when first DPD reagent is added to water with high levels of hardness (precipicates calcium). Cloudiness will not affect test results, will disappear soon.

Question 12

When testing for pH, why do I get a blue/purple color instead of a yellow to red color when using phenol red?

Answer 12

A false pH reading may occur when high levels of chlorine (> 10 ppm) are present. Phenol red is converted to chlorphenol red, which is dark purple when water is alkaline. To eliminate chlorine interference, add 1 drop of chloring neutralizer (thiosulfate) before adding the indicator.

Question 13

Test kits use chemical _____ to perform the chemical tests necessary for pool operation.

Answer 13

Reagents

Question 14

An instrument that compares the color of the testing solution with a manufactured color standard is called a:

Answer 14

Colorimeter

Question 15

The State of Illinois requires the _____ type colorimeter test be used to measure the disinfectant residual.

Answer 15

D-P-D (Diethyl-P-Phenylene Diamine)

Question 16

The chlorine residual must be maintained between _____ and _____ ppm as free available chlorine.

Answer 16

1.0 and 4.0

Question 17

Prepackaged test strips are sufficiently accurate to measure chlorine, bromine, and pH levels, T or F.

Answer 17

F

Question 18

Chlorine test kits may be used to measure the bromine residual by multiplying the result by ________.

Answer 18

2

Question 19

Cyanuric acid is a chemical used as a stabilizing agent against the effects of ________ on chlorine.

Answer 19

Sunlight

Question 20

The maximum cyanuric acid concentration in swimming pools is _____ ppm.

Answer 20

100 ppm

Question 21

Test kits using a ________ solution will measure the pH in a range between 6.8 and 8.4.

Answer 21

Phenol Red

Question 22

The free chlorine residual and pH of the pool water must be tested at least _____ times a day in both the shallow and deep ends of the pool.

Answer 22

2x