Alien Invasion - I want my pond back !

Otto Syracuse · May 23, 2015

If there was a pallet in this field, this thread would BLOW UP!

Eric Salop said:
SIPHON TIME

With the Honda warmed up I set the pump running. I guessed water was going up the hill as the engine sound gradually changed from easy-peasy to a steady determined throb and I set off along the pipeline to double check each joint as the water ran through. All looked good and by the time I made it over the hill water was pouring out of the other end of the pipe. So far so good. Walk back to the sump, pull out the pump connection while keeping the ends under water. A little stiff, pull and twist and pull again and out of the sump came the pipe and into the sump goes my boot. Oh dear, I had just let air into the pipe and water in my boot :ashamed: Empty boot and start all over again.

It was a nice day and I'm the patient type, so nothing really lost. Right, again, pump on pipe, water running, squelch back over hill to check it's coming out, yep, back to sump. This time I made double sure I kept the pipe in the sump as I pulled out the pump. I put my palm over the end and could feel it tug hard. SIPHON Found the end of the flexible suction hose from the filter box and tried to get it on the pipe. It was a bit tight and awkward to get on from my position on the bankside. I probably tried too hard to keep the other foot dry when I should have accepted fate and climbed fully into that sump from the outset, but we live an learn and eventually the hose went on. Turn off the pump and peace descends again. Back over the hill to the discharge end to see it running - except it wasn't a discharge end. It was more like an empty-pipe-laying-on-damp-grass end.

The siphon had stopped. :confused3: What had I done wrong, apart from wearing boots instead of waders

Back to the sump and check filter. Nope that looked ok. Had I miscalculated the relative heights of each end of the pipe ? Didn't think so. I remembered something I had read about dissolved gasses preventing siphons from working. You know how bubbles fizz out when you open a bottle of lemonade ? The same thing can happen in a siphon, gas is released because the pressure in the pipe is lower than outside. Was that it ? Why hadn't I looked into that in more detail. If this water was so gassy it couldn't be siphoned, I would need to go out and buy a few things - lots of fuel and a big slice of humble pie to eat while I tended the pump for days on end.

There could be a much simpler answer. I had put my hand over the end of the pipe to check it was running and then probably obstructed it again as I fumbled with the filter hose. In that time water would still be running out of the discharge end. Could that have been long enough to let air up the outlet ?

Ok, try again and this time make it a smoother change over. Also I reasoned that if I partially bunged up the discharge end until I got it started, it may help restrict the flow enough to prevent air coming back in while I swapped over the pipe in the sump.

Engine on, pump on, let water run for 10 minutes (I'd had enough walking by then to care about checking it was coming out on the other side), smooth changeover, turn pump off, walk up the hill, down other side.

Oh yes, running water. :dance1: Pulled out the restriction and the water came gushing out. :dance1::dance1::dance1:

alchemysa · May 23, 2015

dave1949 said:
I agree with RedNeckGreek.
It could be to keep the end of the hose submerged so it doesn't suck air if the flow stops.

But theres already a big hole in the TOP of the bucket.

dave1949 · May 23, 2015

alchemysa said:
But theres already a big hole in the TOP of the bucket.

It looks like the pipe enters the bucket near the bottom and the overflow hole is in the middle. That could be enough to keep the pipe end in water preventing it from drawing air.

Or maybe it accomplishes nothing, but Eric The Mad Siphonist of Shropshire likes yellow. ??

KevT · May 24, 2015

Naw, he just wanted to give the sheep something to drink out of while empting the pond.:laughing:

SPYDERLK · May 24, 2015

alchemysa said:
But theres already a big hole in the TOP of the bucket.

That would cause head to be reduced by 6". And from the dribble hes getting out its plain theres not much to spare. Flow too slow will allow bubbles to collect.

RedNeckGeek · May 24, 2015

alchemysa said:
But theres already a big hole in the TOP of the bucket.

Allowing the bucket to overflow would soak and soften the ground all around the bucket. The rocks under the exit port keep the water from eroding the ground and keeps the bucket upright.

But let's let the siphonmaster tell us himself in his next installment, which I hope will be along real soon now:laughing:

alchemysa · May 24, 2015

SPYDERLK said:
That would cause head to be reduced by 6". And from the dribble hes getting out its plain theres not much to spare. Flow too slow will allow bubbles to collect.

Yep. Can't afford to lose 6" off a 15 yard fall

the old grind · May 24, 2015

Net fall when siphoning is the difference from source surface to the end the of outlet.
Inlet to remain submerged to maintain flow until surface height matches outlet height.
Siphoning is just water seeking level between two connected sources/points.
Pipe length/friction affects flow more than routing (say up or down).

Eric, IMO you tell a fine tale! Do go on ... :thumbsup:

Subscribed.

Eric Salop · May 24, 2015

The Yellow Bucket
This was suggested by my good friend Joe. He and his brother were the ones who lent me the pipe and were the only people who thought this siphon idea might have a half chance of draining a pond. Now Joe didn't learn a great deal at school, probably because he didn't go that often, but he is smart and one of the worlds best a solving problems in a practical pragmatic way.

I should have put the bucket on from the start. It is to stop air leaking back up the outlet pipe. Without a bucket, air will not get back into the pipe when all is running full bore. If, however, weed starts to block the filter, the water flow reduces and air can come back up the outlet. The whole siphon then has to be primed again after clearing the weed.

With a bucket on and the pipe coming in at the bottom of the bucket, water covers the pipe. The magic of air pressure on the surface of the water stops the pipe from running dry. The hole half way up is another Joe idea to give a better indication of the rate of flow (and as SPYDERLK said, adds a precious few inches to the head of the water column).

Not clear yet? Ok, I can demonstrate the principle of what happens with a totally blocked filter :-

Imagine this basin is the bucket.

And this bottle is the siphon pipe.

(My wife insisted that I kept the food dye in the pic so there is no doubt about where the yellow water in the bottle came from.

)

Just to set everything up, I have kept the top on until the mouth of the pipe (bottle) is below the level of the water in the bucket. Now I take the top of the bottle.

The water stays inside the pipe ( Same principle as used in many inverted water feeders for birds)

If there was no bucket, the water would run out of the pipe.

The sheep appreciated the bucket too. It didn't take long for them to gather around the outflow and take a tentative drink. They don't get to see running water often, as there are no rivers or streams here, only ponds. With their curiosity and thirst satisfied they wondered off, to play no real part in this story (sorry to disappoint you Dave1949).

Water flowed all day Sunday without any problems. A bit of pond weed was finding it's way in and out again, but nothing serious at that stage and all was looking good. Only thing was, I couldn't really see that the level had dropped much, if at all. All along though, it wasn't that actual siphon that concerned me, it was the fact that it had to keep running day and night without blocking. I can hear some of you thinking, if it stops, no big deal, clear the filter and start again.
That wasn't an option because I wouldn't be there.

Back in 2006 we had fields in Shropshire, but nowhere there to live. Our home was a 2 hour drive away back in the county of Yorkshire. Since then we have been lucky to buy part of a dilapidated 1700's brick built barn adjacent to the fields and convert it into the house we now live in, but I better skip all that demolition and construction work as it sounds like you want to get to the aliens ASAP.

I had a full time job in Yorkshire, so once I left on the Sunday, I wouldn't be able to doing anything with the siphon again until the following Friday evening. Nothing else I could really do, except cross my fingers, hope for the best and wait until Friday comes around. In that time I never once went to sleep, or woke up, without wondering how it was doing.

Your Turn
Over to you now for the next few days.

Between now and Friday, you too might like to have a guess at how far the water had dropped.

Flow rate ? I forget, but it should be possible to estimate. The hole in the bucket was 2" diameter. Water was half way up the hole when I left. How fast do you need to pour water into a bucket to get that far up a 2" hole ? If the weather is warm and you have a little time to spare and a bucket (not necessarily yellow), you can perhaps give it a try and let us all know.