Correct Pump & Filter for my 7000L pond?

[shaun]

Hello, wonder if anyone can help. I'm currently digging a 17ft long x 7-9ft wide pond which is 3ft dropping to 4 ft deep. I have worked out that its approx 7000 litres. This is my first pond so am not certain how it wil all work.

I am thinking of either an Oasis Clear pond 80 filter in conjunction with an Oasis Gold 16000 pump.

Or, an Oase Filtoclear 20000 pressure filter in conjunction with an Oase Aquamax 12000 pump.

If I used the clear pond 80 it would have to be approx 2 metres above the water level and 5 metres away from the pump which i'm not sure if it would work as I want a waterfall. This is why I thought a pressure filter would be better as they force the water back out. However the pipe coming out of the pressure filter which would be putting water back into the pond would be 6 metres away from the waterfall and about 1.5m below the pipe entrance level of the waterfall .

any help appreciated, Shaun

 

[shaun]

p.s - I want Rudd, Tench, Grass carp and a few koi in it

 

[vertigo72]

It doesnt really matter. Either way your pump will have to overcome the pressure to get the water from the pond water level to the maximum height of the waterfall. Okay, slightly higher for the non pressurized filter, as that filter will need to be above your waterfall entry, but we are talking a few centimeters here. Whether the filter is high or low, close by or far away from the pump, makes no difference. All that matters is the total pressure, or pump head, which is the result from total distance the water travels, the height and the resistance in case of a pressure filter.

At just a few meters, the length of the tubes and pipes isnt a big concern, depending how wide they are. Bends and 90 degree elbows and the like cause more friction than a few meter of straight piping and pipe width is a much bigger factor. If you go for 40mm or wider, I wouldnt worry about it. The height of the waterfall is likely the biggest factor, that and the resistance from the pressure filter clogging and blocking flow.

 

[shaun]

ok, thanks for that. Well i've worked out that if i go for a pressure filter, the distance to the waterfall would be about 6 metres, and over that distance it would be going to a height of about 1.5 metres. Do you think that that is acceptable for a filtoclear 20,000?

 

[vertigo72]

You mean, if that filter can resist the pressure? I could be wrong on this, but again I dont think it matters, in the sense that the filter is rated for a certain pressure, whether it is the pump that provides it, or the water in the outflow, or a combination, I would guess, is the same. The height will reduce the pumps capacity, so I would think that evens out. If you filter is rated for 20K L/h pump, I suspect it would work with a 10 meter waterfall, the only thing is that the flowrate would be slow or close to zero, depending on pump.

That said, I have no idea what pressure or waterflow the filter is actually rated for, let alone if its any good.