swimming pool construction London


11 December 2014
The importance of pH Level

Two of the most important elements for your pool water chemistry are pH level and total alkalinity – in simple terms pH is an indication of whether the water has acid or alkaline properties and total alkalinity is a measure of how much alkaline substances are in the water. 

While regularly testing your pool water is not the most exciting task, it is essential to maintain your pool and protect swimmers.  Pool water chemistry imbalances do not only result in calcium deposits and corrosion, but swimmers can be left with stinging eyes and other illnesses, so it is essential to get it right.

Hypothetically, the ideal pH level for a pool is 7, measured on a scale of 0 (highly acidic) to 14 (highly alkaline).  Because pool water isn’t pure, however, a pH level of between 7.2 to 7.6 is generally regarded as optimal. Optimal levels for total alkalinity on the other hand are between 80 to 120 ppm.  While both measures influence one another, it is recommended that you balance the levels of total alkalinity before attempting to adjust the pool’s pH level. Here are some of the problems which may occur if you don't keep your pool water chemistry in equilibrium.

Low pH Issue

  • Highly acidic water can be damaging to the structure of the pool as well as its equipment, particularly metal hardware which will be subject to corrosion
  • Stinging eyes, itchy skin and brittle hair are also problems associated with swimming in acidic water 

High pH Issues 

  • Calcium deposits and scale will begin to form, and can be difficult to remove. Calcium deposits can damage the pool’s filtration and other plantroom equipment (heaters, heat exchangers, gas boilers) resulting in expensive repair costs
  • Stinging eyes and other physical conditions are associated with a high pH level  
  • High pH water can cause chlorine to become ineffective, costing you more to sanitise your pool
  • High pH water is also likely to become cloudy, making the water very uninviting – no one wants to swim in cloudy water  

Low Total Alkalinity
If the pool’s total alkalinity is low, metal parts are likely to become corroded and the structure of the pool may become damaged. Low total alkalinity can make it impossible to get an accurate reading of the pool’s pH level, so it is important to resolve this issue first. If you suspect that your pool water has low total alkalinity, an alkalinity increasing product can be added to the pool to bring levels back to normal (contact your local specialist for advice on which product is best suited).

High Total Alkalinity
Cloudy swimming water is one of the most telling indicators that your total alkalinity levels are too high. High total alkalinity usually means high pH level. If you find yourself in this situation, it's advisable to contact your pool specialist for advice/help. The higher your pool’s total alkalinity, the longer it takes to bring back to equilibrium, so preventative measures and regular testing are paramount.

Resolving the Issue
If you suspect that your pool’s pH or total alkalinity is out of balance, don’t hesitate to get in contact with our team of experts – one of our service engineers will be happy to advise you on the best course of action.

While regular testing is the best way to prevent imbalances, this is not always possible, and factors outside your control which disrupt the pool water may occur from time to time. Figuring out the best way to restore equilibrium to the pool water chemistry can be difficult, so don’t worry if you find yourself in this position – we’re here to help!  Call 020 8605 1255 and speak with a service engineer.

At London Swimming Pool Company we specialise in swimming pool maintenance, servicing and refurbishment, so if you have a pool that’s in need of regular maintenance or a facelift, contact us for an initial discussion – there’s no substitute for expert advice. If you have an older swimming pool that needs upgrading, we suggest planning your refurbishment for the autumn, so all the work is done and dusted before the next swimming season.

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