Filtoclear 12000 Pressurised Pond Filter

Oase Pressurised Filtoclear Filter Systems; OASE Filtoclear raised outlet chart

Recommended pond volumes with a raised filter outlet (e.g. watercourse) at 1 metre vertical lift and with 5 metres of 1 1/2" diameter hose between pump and outlet. Also performance with an optional OASE OxyTex Aerator Set installed.

        
Pond Turnover Rates: The pond stocking levels will determine the required turnover rate which in turn determines the required pump flow rate. Typically, an ornamental pond without any fish will require the pond volume to be circulated at least once every 6 hours; an average stocked pond (with up to 1 kg of fish for every 1000 litres) will require circulating once every 4 hours; a heavily stocked pond including Koi (with up to 3 kg of fish for every 1000 litres) will require circulating once every 2 hours. Filtoclear Set pump selections allow for increased pressure drop across the filter foams as they become polluted with pond waste (see the importance of regular maintenance, below). 

Pump Flow Rate: The pump flow rate, typically in litres per hour (lph) or litres per minute (lpm) is determined by the vertical lift, in metres, from the surface of the pond to the outlet pipe AND by the friction losses through the system. The narrower the pipe bore the higher the friction losses, so always use the maximum hose diameter.  There will also be a friction loss caused across the filter media (foams etc), which will increase as they become polluted with pond waste.

Effect of raising the filter outlet: Raising the outlet pipe height, typically for a watercourse or waterfall, will reduce the flow rate from the pump thereby increasing the amount of time it takes to circulate the dirty pond water through the filter. This effectively reduces the maximum pond volume that the filter system can cope with and may mean you will require a larger pump. Please contact us and we would be happy to advise you.

Dissolved oxygen (DO) is a major contributor to water quality. Installing an optimally sized OASE OxyTex Aerator Set will substantially improve water quality and fish and can improve filter performance by up to 25%. See the chart above for improvements in pond volume. 

The importance of regular maintenance (cleaning): High flow rate = effective filtering. As the filter media (e.g. foams) remove dirt and waste from the pond, so the friction loss across the foams will increase, thereby reducing the flow rate and the effective performance of the filter. It is therefore essential, especially for those systems with a raised outlet, to keep the filter foams clean. Fortunately, this is extremely easy with OASE Filtoclear pond filters.        
 

An option worth consideration.

You could split the flow of clean water exiting your Filtoclear filter by utilizing a Y Distibutor, with one branch flowing directly at low level (low head = maximum flow) back to the pond; and the other branch flowing up to the top of your watercourse (high head = reduced flow). By adjusting the Y Distributor outlet valves to suit your preference you can choose to have all or partial flow going to the pond or watercourse. So typically, when there is nobody in the garden you select full maximum, low level flow back to the pond (high level valve closed), thereby achieving optimum filtration. However, when you are in the garden, you can open up the valve to the watercourse to enjoy the pleasant sound of water running down your watercourse. Note, to achieve maximum flow over the watercourse, fully close the low level valve and fully open the high level valve.

The above graphic shows an OASE Filtoclear filter and Aquamax ECO Premium pump connected to a Satellite Strainer via the pump secondary inlet