Results 41 to 48 of 48
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27-04-2018, 08:38 AM #41
Thanks David and Milaz.
Have you guys been keeping up with Zac’s pump testing thread on Kiophen?
He seems to have found that the pumps he’s tested only flow about 75% of the stated manufactures claimed figures. Caused quite a stir lol.
Maybe another thread is required over here for us mortals that’s can’t justify a flowfriend is required that looks at “real world” pump performance.
Loving your guys information.
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27-04-2018, 11:07 AM #42
Yes - I had read it - very good resource.
Manky Sanke has on his great website explained why the pumps performance reality is so much different from max specified flow - this is measured at ideal conditions - with only about 1m of pipe with max possible diameter fiitting the pump outflow in straight line so no one in real life will see it - this is why the Total Dynami Head calculator is so important - as well as flow chart for each pump - from which you can see what the real life flow in given setup will be.
I personally use rule of thumb - that in my pumped setup good pump with max head of min. 5m or more will deliver about 50% of the advertised max flow - and than I look on power consumption as second criteria to decide which one to choose - off course checking also this very valuable forum for real life experience - Feline and others posted very good review of AF DM Vario pumps so it was no brainer to get three of them - very happy with them.
Sent from my SM-G955F using TapatalkYou get what you pay for - or better - what you make yourself.
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28-04-2018, 09:48 AM #43
- Join Date
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Very interesting findings there david and milaz, i have found similar with my pumps, i wont go into detail but i always knew they would be no where near what the manufacturer states. What i do know is that most people are in the exact same boat only are totally unaware or way off on their estimations. It makes me cringe when people make a guesstimate without at least trying a simple bucket fill or chamber drop test like yourself.
The other one that makes me cringe is how many people believe that a pumps head is only from the surface of the pond water . The head on a pump is calculated by the rise from the actual pump unit weather its in the pond or out of pond. If the pump is on the floor say and only pumping across on a horizontal and totally level then there is no physical head but thats when pipe restrictions and back pressure from entering a pond level 1m higher than the outlet plays a part. (I was a marine engineer mechanic in the RN where pumps are a very big thing in numerous areas of enginneering and something i spent alot of time working on, centrifugal and reciprocating etc.. most and a much larger scale than any of us pondys come across )
Sent from my iPhone using TapatalkIts always a work in progress
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11-07-2018, 07:55 AM #44
need to update this because I got the pump flows wrong, I forgot I was draining the drum too which holds 120 litres
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11-07-2018, 09:50 AM #45
I'm a bit confused by this -Total pump head is the sum of suction and discharge pressure. So if you have a pump directly in some water pumping in to a pipe the head of water is how high the water can be pumped above the water surface. That height wont change if the pump is two meters down or a foot down. If the pump is outside the pond it makes no difference provided the losses on the input side are low eg you are using 4" bottom drain pipe with a short run - the head will be only slightly lower than if the pump was in the pond.
Obviously if you put a sieve or even a drum between the drain and the pump then you cant make this assumption - you can presumably approximate based on the working height of the water in the output chamber of the filter though. For example if the output chamber of your drum is a foot down from the level in the pond, then the head of the pump relative to the pond will be a foot lower. The position of the pump doesn't come in to it though does it??
I have no professional expertise in this area - just A level physics a long time a go lol.6000g in ground koi pond
+3000g lily/Anoxic pond attached
29 koi (40 to 65cm)
Bottom drain, Mid water & Skimmer to Drum
JBR boichamber->Blue eco 500 pump ->below surface return.
Blue Eco 240 -> Large MB -> Waterfall -> Planted Anoxic pond (25 baskets)
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11-07-2018, 12:38 PM #46
Great video, you’ve sold me on the jbr bio chamber !!!!
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12-07-2018, 07:44 AM #47
as I said these figures are wrong because I didn't realise initially that draining the bio chamber and timing a certain depth drop, wasn't accurate because it was also draining the drum filter of an extra 120 litres.
I retested twice and I seem to be getting a flow of 22,500 lph give or take, thats with the vario flow pump running at 90 %....which is a whole lot better than I initially thought.
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11-06-2019, 10:04 AM #48
Are you selling the shower in the video ?
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The Daily pond temp thread
Pond still covered, currently 11.6C Been really mild this year as far as pond temps go. ...