Cleaning Water: Making water safe at home, at work and in agriculture

pH Correction

Why do you have pH levels?

Although the pH of pure water is 7, drinking water and natural water exhibits a pH range because it contains minerals and gases. Surface water typically ranges from pH 6.5 to 8.5 while groundwater ranges from pH 6 to 8.5. Water with a pH less than 6.5 is acidic. This water typically is corrosive and soft. Water with a pH higher than 8.5 is considered basic or alkaline. This water often is hard water, containing ions that can form scale deposits in pipes and contribute an alkali taste.

pH correction media

Water with a pH below 7 is acidic and has a corrosive nature. Acidic water corrodes the copper pipework and heating systems found in domestic and industrial plumbing systems. The copper dissolves out and is deposited on fixtures and fittings leaving unsightly green stains. Raising the pH will neutralise the water stopping the corrosivity, removing the metallic taste and can also reduce any iron or manganese contamination. The simplest way to raise the pH of water is to pass the water through a vessel containing slowly dissolving calcium and magnesium salts. These salts slowly dissolve into the water ‘re-mineralising’ the water and naturally raising the pH. The water can be simply passed through the media through an in/out head or through an automatic backwashing filter head. The backwashing head has the advantage of remixing the media and also removing any debris or iron or manganese which may have been oxidised out of the solution as the pH increases.

There are vessel dome hole options in which the pH media can be topped up without having to take off the valve.

How does it work?

Water flows into the valve at the top, down through the media and then up through the ‘riser’ tube in the middle of the vessel. As the water travels through the media the calcium and magnesium salts slowly dissolve into the water raising the pH. Any iron or manganese contaminants in the water will also drop out of solution and are trapped in the vessel. There are timer options that can be set to automatically self clean (backwash) and wash away any of the accumulated iron and manganese. The in/out pH units have the water flowing the opposite way down the riser and up through the media. This keeps the media free and clean.  Manual backwash valves are available.

How to size

On average 160 litres of water is used per person per day. This normally occurs in two peak periods, one in the morning and one in the evening. A family of four typically uses 700 litres of water per day but may use 300 litres in an hour in the morning. Larger households, farms, stables and irrigations systems all use more water. When sizing a system the peak flow rate need to be taken into account. The size of the pump also needs to be taken into account as these filters normally use twice the service flow rate to lift the bed and backwash away the trapped iron and manganese. If the backwash flow is not available two smaller units running side by side is often a good solution

A water quality test report should be obtained to ensure the appropriate equipment is suggested.