Thread: New Pond Piping Help

Personally I would use a smaller bottom drain, 3" or even 2", with matching pipe, you'll get faster flow through to keep pipes clear and 1.5" pipes everywhere else. Even a 10K LPH vario pump will do nicely, probably at a reduced running, maybe split return 30 - 40%, to pond, 60 - 70% to Bakki shower.

I have a 1600 Gallon pond into EasyPod via 3" pipe, with a Swell Vario 10K pump running at most below 50 Watts, 1.5" return and a separate Skimmer to Bakki shower with a Grundfos low wattage pump.

Thanks KIOgon, that's much appreciated. I have ordered 1.5in piping and fittings.
Another thought has crossed my mind about a skimmer.
My skimmer on my old pond is connected using 1.5in piping, if I was to plumb this into the bottom drain piping using a tee and a reducer, would the gravity draw be sufficient to pull enough water through the skimmer to make it effective and carry it through to the filters?
Is your Grundfos a central heating pump?

In a word - no. Skimmers IME need a lot of flow through to do any good, the only way I've found that works with 1.5" pipe is using a central heating pump after a pre filter basket. Grundfos are best, but the general design I believe give practically as much 'suck' as 'blow', something many pond pumps don't - they're all blow

Originally Posted by Hopalong30

Can the Grundfos pump be used outside or does it need to be housed?

They are water resistant to splashes but not to heavy rain so they can go outside of a plant room if they are sheltered so rain can't fall on them - even wind blown near-horizontal rain.

Many years ago, I had a big pond in a big garden with a Grundfos 15-50 IIRC, running a waterfall, outside but under a paving slab, (not to be recommended), but it lasted 13 years .

I wouldn't advise one outside without some form of weatherproof cover.

I'm not really understanding the concept of blowing but not sucking in a fully piped inlet/outlet scenario.
In physics terms there is no such thing as "suck". Won't bore folks with an explanation.

In an open to atmosphere systems such as in ponds, failure of a pump to deliver its rated output is usually due to inadequate flow to the pump inlet.
In this case the pump vanes push through the water rather than pushing it along and in extreme cases (with a powerful pump) you get cavitation.
I am guessing that CH pump impellers are designed with minimal "water slip" (a bit like car engine oil pumps). So I get how they would do better in a "high friction" environment.
However you can't have the "blow" ever being more than the "suck".
Good input flow to a pump is down to:
Head - the more the better - more gravitational potential energy to push water to replace that being "blown" forward.
Pipe length - the shorter the better - less friction.
Pipe diameter - as large as possible - lower velocity and lower surface contact - less friction.

Is there any way you could improve one or more of these in your system?