Product History

Prior to the first CGF filter being placed into service in 1976, there were basically three types of filters in common use. These were:

  • Gravity sand filters constructed from reinforced concrete,
  • Pressure sand filters constructed from reinforced concrete, and
  • Pressure sand filters fabricated from protected Carbon Steel.

Today, many of these earlier types of sand filters have outlived their useful service and are widely considered to be antiquated and inappropriate for the requirements of modern Health standards.


The main disadvantage with carbon steel has, and always be, corrosion. Protection against corrosion is limited by the coating materials that are available and the skill of the coating contractor to apply these coatings in a confined space. Even when all of these variables are strictly controlled, the abrasive nature of frequent backwashing (in combination with aggressive pool chemicals) quite often results in protected carbon steel filters being subject to comparatively high maintenance costs and short service life.With regard to concrete filter vessels, the difficulties encountered are often much more diverse and complex. The types of problems include erosion, corrosion, leaks, loss of filter capacity, and structural failure
Protected Carbon Steel Filter due to pressure, vacuum, and or ground movement/settlement. From an showing several attempts to engineering point of view, concrete pressure filters, require a substantial serious water leaks. steel component (particularly at the corners) and if properly assessed
are expensive and difficult to construct.

Based on the national acceptance of CGF ‘s first fiberglass filters (Model HS-16, now known as MHS1500), the 1160 Series was released in 1980. This was shortly followed by the 2000 Series and more recently the 1500 Series. CGF’s product range now includes sixteen (16) horizontal filters providing filter areas from 1.5m2 to 7.25m2 in single vessels. Whilst generally known for their horizontal filters, CGF also manufacture a comprehensive range of vertical fiberglass filters.



The advantages of fiberglass pressure filters are innumerable. Apart from being resistant to corrosion and erosion, they are also comparatively lightweight pressure vessels that are transportable and easy to install. Given a clear understanding of the application, just about every conceivable requirement can be accommodated with a well engineered fiberglass filter vessel.

Unlike some FRP filters, CGF filters are “contact moulded” using an activated resin in combination with glass fiber filaments (generally in the form of chopped strand mat and or woven rovings). This versatile With service history spanning almost 30 years & predictable manufacturing method, enables complex vessels to be
the MHS1500 has become an icon in the constructed with a wide range of design features that include different commercial pool Industry types of access hatches, connection nozzles, inspection ports, etc.,

Apart from FRP construction, the modern principle (of allowing solids to be collected within the depth of the filter media) has resulted in a major reduction in overall tank size, which has resulted in lower unit costs, easier shipping, shorter installation times, and much smaller more efficient plant rooms.