Oase Gravity Filter Systems: Pond volumes with raised filter outlet
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.
Effect of raising the filter outlet: Raising a gravity outlet, 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 the resultant reduction in pond volumes are stated in the charts 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). 
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 pond filters.  

 

Sets include Biotec Gravity Filter, self-cleaning UVC and Aquamax Eco Pump. Hose can be ordered from our Accessories page, Biotec discharge pipes from our Filter Accessories page.
Filter Set Part Number Filter Model Bitron Ultraviolet Clarifier  Pump Model Height of filter outlet above the pond water surface Pond volume in litres
No Fish Average Fish Stock 1kg/1000 litres Koi/High Fish Stock 3kg/1000 litre
Biosmart Set 1A 57375A Biosmart 8000/9W Integral 9 watt Aquamax Eco 2000 50 cm 3000 1500 N/A
Biosmart Set 1B  57375B Biosmart 8000/9W Integral 9 watt Aquamax Eco 4000 50 cm 4000 2000 1000
Biosmart Set 2A  57377A Biosmart 16000/11W Integral 11 watt Aquamax Eco 2000 50 cm 6000 3000 1500
Biosmart Set 2B 57377B Biosmart 16000/11W Integral 11 watt Aquamax Eco 4000 50 cm 8000 4000 2000
Biosmart Set 2C  57377C Biosmart 16000/11W Integral 11 watt Aquamax Eco 6000 50 cm 12000 6000 3000
Biosmart Set 2D  57377D Biosmart 16000/11W Integral 11 watt Aquamax Eco 8000 50 cm 16000 8000 4000
Biosys Set 2B  57413B Biotec 10.1 Bitron 24C Aquamax Eco 6000 50 cm 20000 10000 5000
Biosys Set 2B  57413B Biotec 10.1 Bitron 24C Aquamax Eco 6000 1 metre 10000 5000 2500
Biosys Set 2  57413 Biotec 10.1 Bitron 24C Aquamax Eco 8000 50 cm 25000 14000 8000
Biosys Set 2  57413 Biotec 10.1 Bitron 24C Aquamax Eco 8000 1 metre 18500 10500 6000
Biosys Set 2  57413 Biotec 10.1 Bitron 24C Aquamax Eco 8000 1.5 metre 12500 7000 4000
Biosys Set 2C  57413C Biotec 10.1 Bitron 24C Aquamax Eco 12000 50 cm 35000 18000 10000
Biosys Set 2C  57413C Biotec 10.1 Bitron 24C Aquamax Eco 12000 1 metre 26000 13500 7500
Biosys Set 2C  57413C Biotec 10.1 Bitron 24C Aquamax Eco 12000 1.5 metre 17500 9000 5000
Biosys Set 2D  57413D Biotec 10.1 Bitron 24C Aquamax Eco 16000 50 cm 45000 20000 12000
Biosys Set 2D  57413D Biotec 10.1 Bitron 24C Aquamax Eco 16000 1 metre 34000 18000 9000
Biosys Set 2D  57413D Biotec 10.1 Bitron 24C Aquamax Eco 16000 1.5 metre 22500 10000 6000

 

Sets include Screenex Gravity Filter, self-cleaning UVC and Aquamax Eco Pump. Hose can be ordered from our Accessories page, Biotec discharge pipes from our Filter Accessories page.
Filter Set Part Number Filter Model Bitron Ultraviolet Clarifier  Pump Model Height of filter outlet above the pond water surface Pond volume in litres
No Fish Average Fish Stock 1kg/1000 litres Koi/High Fish Stock 3kg/1000 litre
Biosys Set 3A  57414A Biotec 12 Bitron 36C Aquamax Eco 8000 50 cm 32000 16000 8000
Biosys Set 3A  57414A Biotec 12 Bitron 36C Aquamax Eco 8000 1 metre 24000 12000 6000
Biosys Set 3A  57414A Biotec 12 Bitron 36C Aquamax Eco 8000 1. metre 16000 8000 4000
Biosys Set 3  57414 Biotec 12 Bitron 36C Aquamax Eco 12000 50 cm 40000 20000 10000
Biosys Set 3  57414 Biotec 12 Bitron 36C Aquamax Eco 12000 1 metre 30000 15000 7500
Biosys Set 3  57414 Biotec 12 Bitron 36C Aquamax Eco 12000 1.5 metre 20000 10000 5000
Biosys Set 3B 57414B Biotec 12 Bitron 36C Aquamax Eco 16000 50 cm 45000 22000 12000
Biosys Set 3B 57414B Biotec 12 Bitron 36C Aquamax Eco 16000 1 metre 33750 16500 9000
Biosys Set 3B 57414B Biotec 12 Bitron 36C Aquamax Eco 16000 1.5 metre 22500 11000 6000
Biosys Set 4  57415 Biotec 18 Bitron 55C Aquamax Eco 16000 50 cm 50000 25000 13000
Biosys Set 4  57415 Biotec 18 Bitron 55C Aquamax Eco 16000 1 metre 37500 18500 9500
Biosys Set 4  57415 Biotec 18 Bitron 55C Aquamax Eco 16000 1.5 metre 25000 12500 6500
Biosys Set 4A 57415A Biotec 18 Bitron 55C Promax 20000 50 cm 60000 30000 16000
Biosys Set 4B 57415B Biotec 18 Bitron 72C Promax 20000 50 cm 70000 35000 20000
Biosys 7/160/72 7160110 Biotec 36 Bitron 110C Aquamax Eco 16000 50 cm 90000 45000 22000
Biosys 7/160/72 7160172 Biotec 36 Bitron 72 Aquamax Eco 16000 1 metre 70000 35000 17000
Biosys 7/200/72 7200110 Biotec 36 Bitron 72 Promax 20000 50 cm 110000 55000 27000
Biosys 7/300/72 7300110 Biotec 36 Bitron 72 Promax 30000 50 cm 140000 70000 35000
Biosys 7/300/72 7300110 Biotec 36 Bitron 72 Promax 30000 1 metre 100000 50000 25000