Why Water Testing Matters?

It can be tempting to skip testing your pool water, but we cannot stress its importance enough. Water testing is essential in protecting not only your investment, but also your family’s health and enjoyment.

Water testing is the first step in ensuring your pool is perfectly balanced. A balanced pool protects your pool equipment, your family against itchy skin and eyes and enables your sanitiser (and other chemicals) to work as effectively as possible.

You should aim to test your water at home at least once a week, using Test Strips or Test Kits to ensure your family is swimming in safe and healthy water. We also recommend getting your water professionally tested at least once a month, by your Poolcare 54A Hewletts Road Mount Maunganui , who has the latest, state-of-the-art water testing equipment and software.

To help you understand how to best maintain your pool during summer, listed below are some terms you should familiarise yourself with, and the levels they should sit at. Detailed descriptions of what each term means are also listed below.


Term How it’s measured
Total Alkalinity Test total alkalinity (TA) first because a correct level will maintain your pH levels. Note, different pool surfaces require different TA levels.

o    Concrete/tiled/pebblecrete: 80 to  125ppm (ppm = parts per million)

o    Fibreglass:                                  80 to  120ppm

o    Other: (eg painted/vinyl)        120 to 150ppm

Chlorine (Sanitiser) 1.5ppm to 4.0ppm
pH pH is measured on a scale from 1 [acidic like lemon juice] to 14 [alkaline like cloudy, soapy water]. Ideal range 7.2 to 7.6
Calcium Hardness Different pool surfaces require different Calcium Hardness levels.

o    Concrete/tiled/pebblecrete: 150 to 200ppm

o    Fibreglass:                                  175 to 225ppm

Cyanuric Acid 30ppm to 90ppm


Total Alkalinity (TA)

TA is the measure of buffering minerals present in the water, these minerals are critical to prevent the pH from shifting or bouncing.


pH is a measure of the acidity of the water and is considered the most critical element of water balance.

  • If the pH level in your water is too low, the water is acidic, causing corrosion, itchiness, sore eyes, over active chlorine and potential equipment damage.
  • Furthermore, a spike in the pH level indicates your water has become alkaline and may start to cloud. Cloudy water leads to a build-up of scale and corrosion of your pool equipment.
  • You can lower pH levels by adding Poolcare pH Decrease and raise them by adding Poolcare pH Increase


Chlorine is a sanitiser that keeps your pool free of harmful bacteria. If the chlorine level in your pool has dropped, your bacteria levels will spike. We recommend using Poolcare Pooltabs for slow release stabilised sanitation to control bacteria. If your chlorine levels need a quick boost, we recommend Poolcare Pool Granules– it’s easy to use with no need to pre-dissolve.  Call in to Poolcare and ask about the best chlorination solution for your pool or spa.

Calcium Hardness

Calcium hardness is the measurement of how much calcium is present in the water. It’s necessary in your pool, otherwise the water will leach calcium from your pool walls, equipment, and even your fingernails!  Low calcium levels in your pool water can cause corrosion in your pool equipment, and high levels can create scale. To prevent this corrosion, we recommend using Poolcare Water Hardener to increase calcium hardness.  If you have high calcium levels, we recommend using a product to reduce the calcium levels or to prevent excess calcium from forming scale.

Cyanuric Acid

The role of cyanuric acid is to protect your chlorine from being broken down by the sun (50% of chlorine is lost to sunlight in just 60 minutes)! Cyanuric acid helps keep your chlorine from breaking down, ensuring your water is sanitised and safe for longer. If your levels are low, we recommend using Poolcare Stabiliser.

While it can seem like a drag, regular water testing is so important in keeping your pool safe and healthy for swimming. And don’t forget that your water balance is significantly affected by rain and pool parties, so make sure you test your water after any downpours or events.

Tips for Using Test Strips

  1. Collect a water sample from the pool at elbow depth and away from jets.
  2. Dip a strip into the water, quickly in and out. No need to let it stay submerged or soak.
  3. Hold it still in the air for about 15 seconds. No shaking!
  4. Compare the strip to the guide on the packaging, and match up the colours on both.
  5. Adjust your chemicals accordingly.

Tips for Using Test Kits

  1. Collect a water sample from the pool (at elbow dept and away from jets) in the collector provided in the test kit.
  2. The large vial is for pH testing, add the recommended number of drops of phenol red or No 2 solution to the water.
  3. On the side designated for chlorine testing, add 1 DPD No.1 tablet to the water.
  4. Hold the vial up to a white background, and compare the colours of the water to the colour scales on the collector. The redder the water, the higher the pH, and the yellower the water, the higher the chlorine level.

Important: If the levels are low, the water colours will be fainter, and can be difficult to see. For higher accuracy, be sure to hold the vial up to a white background. Just a sheet of printer paper will do.

When was the last time you tested your pool water? 

If you are unsure of your pool’s health, come into Poolcare Ltd Mount Maunganui where We carry out complimentary in-store water testing for spa and swimming pools for our customers.

We ask that you bring in approximately 500ml of water and we carry out full testing of pH, Alkalinity, Calcium, sanitiser level, dissolved solids and metals.  We will make recommendations based on your pool or spa size, so that the guess work on quantities and specific products is removed.  We can also advise on more specialised problems you may possibly have with algae, metals, cloudiness, sanitiser inefficiency, and staining.