Frequently Asked Questions

OC stands for Open Cell and OC-1 is an open cell mechanical filter that utilises open cell filtration technology to filter water to a high quality, whilst also having the potential to save water and energy.

OC-1 is made from HDPE plastic.

OC-1 is made in Wigan, England.

OC-1 works by settlement not entrapment (like sand or glass). Each cell is in essence a mini settlement tank. Any debris entering the filter bed will lose kinetic energy as it passes through each cell until it settles out in or on one of the elements. As there is 80% free area in a piece of OC-1 compared with sand’s 5%, OC-1 can hold more debris (at least 20 times more than sand) before backwashing is required. Its large free area means there is less resistance to water flow, which means a greater flow at less pressure can be obtained.

As mentioned above, OC-1 can hold more debris than traditional medias before a backwash is required, so the frequency of backwashing can be reduced. The amount of water required to backwash and clean OC-1 is also less than other traditional media.

The free open area of OC-1 means that there is less resistance to water than with traditional medias which allows for either a smaller pump to be used (using less electricity) or a variable speed pump can be used at a lower speed to reduce electrical consumption. Energy can also be saved due to less backwashing, this saves on heating water that is then backwashed down a drain. As an example, we expect to see approximately 20% greater flow through OC-1 than through sand. Using the pump affinity laws, this means the speed of the pump can be reduced by 20% to achieve the same flow and this equates to a reduction in electricity consumption of 48.8%.

OC-1 provides a constant flow rate, at a constant pressure, so turnover times and the circulation of the water is always maintained. Any pool equipment which requires a constant flow (e.g. heater or salt chlorinator) will never stop working on “no flow”. The filtration quality is also constant, unlike sand or glass which varies according to how blocked the media is. OC-1 is also 87.5% lighter than sand making it easy to handle and ship around the world. The open nature of OC-1 ensures there are never any “dead spots” within the filter bed. All areas of the filter bed will be oxygenated and have flowing water. Traditional medias can suffer from “dead spots” in the filter bed and these can then harbour anaerobic bacteria which have the potential to be harmful to health.

OC-1 has been independently tested by IFTS (Institut de la Filtration et des Techniques Separatives) in France to EN16713-1. We also have a large number of swimming pools running on OC-1 throughout the world. Case studies, along with the IFTS report can be found on the website www.ocmproducts.com

OC-1 can be bought through Pool Shops in the UK and throughout many countries worldwide. If you are experiencing any problems buying the product, please e-mail OC-1@certikin.co.uk to find your nearest stockist.

No, other open cell medias are for use in biological filters and use bacteria to filter out nitrogen based waste products. They have not been designed as a mechanical filter. They will float, require up flow water delivery and not down flow which is used in sand filters.

OC-1 will work in any sand / glass media filter, however minor modifications will be required to the laterals to ensure a better even flow through the media bed, this also has the benefit of reducing head loss through the filter.

Yes, full instructions can be found on www.ocmproducts.com The laterals need to be drilled with an 8mm drill bit to ensure a full and even flow throughout the filter.

The potential problem is that the laterals could block, from the outside to the inside. This could cause a rise in pressure or the OC-1 could move to the outside of the filter as the water is moving very quickly through the centre of the filter. As the OC-1 is easy to remove, the modification to the laterals should be done as convenient. Backwashing the filter will buy you time before the modification, if required.

Under normal use this may not be required as the OC-1 will sink. The diffuser provides a belt and braces approach to ensure the OC-1 cannot escape during backwash.

Yes, you can, a modification is required to the laterals and it may be necessary to also use OC-3 to ensure no loss of OC-1 when backwashing. OC-3 is a large floating media whose only function is to prevent OC-1 from escaping during backwash.

Under normal use this may not be required as the OC-1 will sink. The OC-3 provides a belt and braces approach to ensure the OC-1 cannot escape during backwash.

OC-1 can be used in a wide range of filtration rates from 20m3/m2/hr through to 60m3/m2/hr. It is more important to ensure there is good circulation in the water (no dead areas with no circulation) and that the turnover times of the water per day, are within acceptable standards.

Yes, OC-1 will work.

Yes, OC-1 will work.

Yes, OC-1 will work.

Please see the available chart or use the formula – kg of sand and gravel divided by 1.59 = litres of OC-1.

OC-1 filters out particles as small as 1 micron. An independent test report can be found on www.ocmproducts.com website.

Sanitiser (chlorine or bromine), pH and water balance should be kept within usual recommended levels to ensure that the water is safe and healthy to swim in and that the equipment used on the pool is protected. However, there is no need to use flocculants on a regular basis and in fact they could be counter-productive if used in excess.

Automatic dosing of liquid flocculant or PAC should be avoided, without any fine particles to bind to the chemical it will collect at the bottom of the filter or pool and will not be effective. Their use should be restricted to as and when required.

OC-1 can be used with a nozzle plate filter, however modifications would need to be made to the nozzles to make them compatible with OC-1.

We recommend a life span of 5 years with OC-1, at this time OC-1 should be inspected and cleaned or replaced.

OC-1 will require less backwashing than traditional medias, however each pool is different, we recommend initially backwashing at twice the normal interval used with sand and then this could possibly be increased as the clarity / chemicals in the water dictate. Do not backwash too regularly, once a week is the maximum that we would normally recommend.

Backwashing should be done on a time basis i.e. once a week, fortnight or month.

Yes, rinsing is very important and we recommend rinsing at least as long as the backwash.

Yes, the same rules apply to the pool water as before and dilution of the pool water to keep certain chemicals in check does not change. One way to check to see if the pool water needs dilution is to check the TDS (Total Dissolved Solids) in the pool, TDS level should be less than 1,000mg/l above the source water.

In the same way as you would with other filter medias. This would involve closing off the multiport valve, draining down the filter and using any specialist winterising products.

Yes, after its life cycle OC-1 can be taken to a recycling centre and disposed of as a plastic.

Yes, you can, however you are not taking full advantage of the increased flow through OC-1 and the electrical savings that this can offer by reducing the speed of the pump but maintaining the original flow through a traditional media.

Pool water temperature does not affect OC-1. However, it can affect the pool water chemistry and the water should be monitored and treated accordingly.

Yes, you can. We have had good results, please see the Alan Shearer Centre Case Study on www.ocmproducts.com

By clicking on www.ocmproducts.com or contacting OC-1@certikin.co.uk

Yes, but do ensure the amount of time the pump is running is suitable for the type of pool.

Yes, you can. See Question 17.

Yes, you can change the pump speed without any problems with OC-1. However, you do want to ensure good circulation through the pool with no dead spots and also to maintain a turnover speed suitable for the type of pool.

No, it is not, the use of an oxidiser in the swimming pool means that OC-1 is only used as a mechanical filter. If an oxidiser is not used then OC-1 along with traditional filters would start to become a biological filter.

Yes, it is. OC-1 provides a static media bed and only at extreme flows will it move during backwash.