chemical levels do I need to test for regularly?
four main tests to perform with a test kit are pH, chlorine (or
other sanitizer residual), Total
Alkalinity and Calcium
Acid levels should be maintained on outdoor pools which use chlorine. Mineral content, Total Dissolved Solids and Acid or Base Demand
tests may also be performed as needed.
often do I need to test the water?
should say everyday, but I realize that's a bit much for most people.
Commercial pools are required to check chlorine levels every hour
and record their findings in a log, however the
"backyard lifeguards" should check their pH and chlorine levels
at least twice per week. Chlorine should be fed continuously through
a feeder device
to maintain a consistent level. Total Alkalinity and Calcium Hardness
levels tend to fluctuate less, so weekly testing should be O.K.
are the recommended levels?
pH: 7.2 - 7.8
Chlorine: 1.0 - 2.0 ppm
Alkalinity: 80 - 120 ppm
Hardness: 180 - 220 ppm, though some say
200 - 400.
Acid: 40 - 80 ppm
Dissolved Solids: below 5000 ppm
long do my reagents last?
one season. Reagents lose
their strength over time and can also be ruined by direct sunlight
and temperature extremes. Replace your reagents annually. Reagents (or test strips) that give suspect readings should be looked at suspicously.
I use reagents from other test kits with my test kit?
drop size, concentration and color variation will provide inaccurate
results. Only use the reagents made by the manufacturer of your test kit. Same with certain digital strip readers or even smartphone apps that read strips are most accurate measuring their own strips.
I use a chlorine test kit for bromine?
you have a DPD
test kit, you need simply multiply the test result by 2.25 to
obtain the bromine equivalency. This works because bromine is over
twice as dense as chlorine. Yes, you can use a dpd test kit and extrapolate the bromine reading in a pool or spa.
test kit shows no Chlorine, even though I know it's there...
chlorine levels are excessively high, the content can bleach out DPD,
a reagent commonly used for chlorine testing. Either dilute the sample
with chlorine free water, or double the # of drops of DPD, and multiply
or divide accordingly.
has been evidence that excessively high levels of stabilizer,
acid, can cause a phenomenon called chlorine lock. Levels above
100ppm of cyanuric acid (CYA) may prevent chlorine from registering
and possibly sanitizing. Lower CYA levels by dilution.
you smell chlorine in the water, you are very possibly aware of combined
chlorine, known as chloramines. These will not register in a test
for free chlorine. A good DPD test kit will allow you to test for
total chlorine levels and free chlorine levels; the difference being
the combined levels. If trace amounts of combined chlorine is above
.3 ppm, you may need to shock the
pool to break the bond of chloramines; this shock level is around
I test for pH, I get a purple color...
your reagents are in good condition, a purple color in a pH test is
an indication of chlorine levels being too high and interfering with
the test. Add a drop of thiosulfate reagent (#7 in the Taylor test kit) to remove the chlorine
from a new sample, and test again.
type of test kit do I need?
are many different types of test
kits commercially available. If you are concerned about water
balance, (and you should be) you will want to spend more for a
nice kit. The basic "duo" test kits, available for about
five bucks, are usually OTO chlorine and pH testers only. You may
wish to spend more for a DPD chlorine kit, which measures free, combined
and total chlorine levels (OTO measures only free levels). Also important
is the ability to test total alkalinity and calcium hardness. Acid
demand and base demand tests will allow you to perform a titration test
on your pH sample. Simply count the # of drops to determine, with
the help of a chart, exactly how much acid or base is needed to adjust
the pH. A "four-way"
test kit will test pH, chlorine, alkalinity and
Test strips are available with "Litmus test" technology.
These are "dip & read" strips of paper that turn colors
indicating levels of pH, alkalinity and chlorine in the pool. Fairly
simple to use, however, it seems that they may not be quite as accurate.
Modern devices will improve accuracy and help those who cannot discren the colors very well. Your pool professional can check the water for metal presence, cyanuric
acid levels and TDS (total dissolved solids).
If you have a biguanide water
treatment system or a chlorine generator, you'll obtain special test
kits from these dealers.