Wednesday 4 March 2020

Moulton Equine Therapy Centre – Behind the scenes Pt. 1 Water testing




We take water quality at the equine therapy centre very seriously. The water in the swimming pool is tested and chemically balanced every day, the readings are then recorded in a log book. It is very important that the readings are accurate as small changes in a reading can mean an actual large change in the pool water quality.

Why do we test the water?
It is important to test the water in the pool to ensure the pH and chlorine levels remain balanced. Chlorine is a disinfectant and is added to the water to kill microbial pathogens. A correct disinfectant level is crucial to maintain biosecurity.






What do we test?
We take three separate tests for the chlorine levels; the free, total and combined chlorine.  It is imperative to take the pH reading too as the chlorine is most effective at a specific level of pH. We use a photometer to take these readings. The photometer gives the reading by passing light through a coloured 10ml sample of water.

Any dirt that comes off of the horses when they are using the equipment has a tendency to raise the pH to be more alkaline. Chlorine is more effective between the range of 7.2 – 7.4, therefore if the photometer gave a reading of above 7.4, acid will be added to the pool to reduce the pH level, if the pH was too low, alkaline would need to be added to increase the pH.





Free chlorine is what attacks the pollutants in the water.  When the free chlorine combines with the pollutants it becomes combined chlorine.  High levels of combined chlorine are bad and are what give off noxious gases and can cause skin irritations.

To get the combined chlorine reading we test for the free and total chlorine and use this simple sum: Total Chlorine – Free Chlorine = Combined Chlorine






Free chlorine should outnumber Combined Chlorine at a ratio of 2:1, so that there is always enough free chlorine ready to attack any pollutants that may be introduced into the water.   If the combined chlorine levels read more than the free chlorine levels this means we will need to add more chlorine in the pool to re-balance the levels. As these chemicals can be dangerous in high concentrations, we always wear a gas mask, gloves and an apron when adding them to the pool.