What Type of Pond Pump?

I have two circular ponds - North and South - with a straight "canal" connecting them

South is the lowest highest, North the highest lowest. I have a submersible pump in North that pumps to the South end of Canal so the water flows round. At the time North South pond was not completed.

I've now completed North South pond, and I want to change it so South North pumps to North South, and the water flows back through Canal.

We've been using an extension lead to the pump in North pond until now.

However, there is already a proper armoured cable going to South pond (the previous people had a fountain in South pond which, at the time, wasn't connected to anything else.

So my question is:

Can I put a "pull" pump in South pond, instead of the current "push" pump in North pond - then I won't have to do any extra wiring.

My understanding is that pumps work better pushing rather than pulling, and I suppose a pull pump may even need priming (which may not be too bad, it will only need doing once in a blue moon)

Thanks



OP = Old pump
NP = New pump location and, in green, extension to pipe run
"Fount" = fountain to be driven by new pump.

Uplift from North to South about 2' - 3', and fountain another 2' - 3'

 

Don't really understand the push or pull bit.

But if you put a strong enough pond pump in the lower pond it'll pump water up the upper pond and also to the fountain. They have two connections on bigger pumps.

My two pond pumps for the back pond are 125 watt and pump for a distance of 90 feet with a 5 feet head. They pump through a 2 inch black corrugated pipe.

 

Sorry. Currently the pump is in North pond and "pushes" uphill to the higher South pond

If I get a new pump and put it in South pond it will have to "pull" from the lower North Pond

 

No experience of using a pump to pull water but my first thought would be that you would need a stronger unit than one that pushes.
I'm only guessing, though. I'm not qualified to advise.

 

Hi Kristen, sorry I don't understand either, please allow me to explain.
I understand what you mean by push and pull.

Push = pushes the water up hill

Pull = pulls the water up hill

What I don't understand is: If the North pond is higher than the South pond, and it has a pump in it, how does the water get back without a pump? since water can be pumped to any level, but only flows down on its own accord.

(You said its pumped from North to South, so how does it get back from South to North if North is higher than South?)

General information about pumps

A pump actually pushes and pulls at the same time.

If you put a pump in a container with the outlet pointing up, the water is PUSHED up the pipe to the outlet, but PULLED into the pump impeller.

Sometimes you do get a pump mounted above the water level with a suction hose in the water. An example would be a fire engine getting water from say a river for a fire as the hydrant is too far.

But pumps above the liquid level are not often used because the suction hose has to be very wide and strong enough not to collapse, so it costs more, the pump often needs priming* and not all pumps can "pull" and above all, it is very inefficient.

* You can get a one way valve just for the job, its called a foot valve, but they can be expensive and can reduce the flow.

So to keep costs down people pump water up (PUSH)

Generally bigger pumps don't have two outlets. Its the pipework that comes with them that has multiple outlets, but these pumps are often little use for a good water flow as you will be doing.

Not all pumps are the same.

In short

Fountain pump: Pumps to a high head height

Filter pump: Pumps a lot of water, but only to a low head height

Sump pump: Pumps a lot of water to a high head height, but very expensive to run.

A pump is chosen acording to the required task, not "That one over there, because it costs less" people that do that find out the hard way, not all pumps are the same.

Suggestion

If I were you, I would buy two pumps, one a water filter pump, to pump to a filter and between your two pools, and another pump for a fountain. That way you can just the fountain off at night and leave the filter running (with a UV) 24/7 which is what a biological filter needs

 

Gravity will do that bit. I reckon I typed something wrongly, sorry. South is higher than North.

I already have electricity at South. Installing electricity for North will be expensive.

Hence if I can put a pump in the South pond I don't need to pay for additional electricity installation.

The pipe is MDPE Blue water pipe. I don't think it would collapse as I can;t even bend it to go round a gentle corner! but the bore may not be wide enough (although it would be easier to replace that than do the electricity cable).

Thanks for your help chaps.

EDIT: OK, I've now re-read my original post, and corrected it. Sorry for the confusion. Don;t put me in charge of running the country! (On second thoughts, I couldn't do a worse job than the lot we have had for the last 50 years ...)

 

Well, the answer is probably; just run an extension electricity cable at the bottom of the canal from the South Pond to the North Pond so that your pond'll work there.

 

I'm not really happy with an extension cable (notwithstanding I've been doing that for a couple of years!!!)

We have armoured cable to the South pond. However, if we extend it to the North pond the voltage drop will be too great ... so we will have to run a new cable all the way from the fusebox to the North pond ... which is rather a long way, and therefore rather expensive :(

And thus my great idea that if I could put the pump in South pond I would save the money on cabling.

 

With all your crossings out, it makes me for one, somewhat confused. Sorry.

Are you saying you have it all running but via an extension lead? But the steel wire armoured cable is at the other pond?

 

I did the crossing out so people would know what I changed and not have to read the whole thing again.

"Are you saying you have it all running but via an extension lead? But the steel wire armoured cable is at the other pond?"

That's exactly it :thumb:

Currently extension lead to pump in North pond.

I have armoured cable to South pond. If I can put a new pump there (which will have to Pull rather than Push, as it is at the high end) I will be able to use the proper armoured cable.

The armoured cable cannot be extended to the existing pump in North pond (because cable would be too long and voltage drop too great). (Existing pump need replacing anyway, so opportunity for change)

Sorry for all the confusion, if I'd got it right-first-time I would not have mucked you all about so much.

 

Sorry, but something is still bugging me about the water direction and location of the pumps but I can't see what it is just now.

But that aside, you say its working as you want it, I know you said

But if you extend the cable to the required length it can not be too long, since it is at the required length.
Voltage drop is not a problem since you do not yet know what the load will be, and when you do you can install a cable with a bigger CSA to compensate IF required. Steel wire armoured cable is not that expensive, or are you just unsure / not confident on how to do it?

As for a pump that will "PULL" as I have said, its very inefficient and will need an oversized pump, and pumps do not have listed on the box how much they can "PULL" (Only how much they can "PUSH" and to what height) so any pump you do get will be pot luck if it works. As I said previously, a pump should be chosen for the job it is to do, never pick "That one over there" Just because its cheaper.

How about a picture or more?

 

I got the sparky to look at it (some months back) when he was doing some other bits and bobs here and he calculated the voltage drop for the currently installed armoured cable and said it would run my current pump, but if we extended the cable it would be too long. The existing armoured cable is pretty skinny - probably been in there a while I expect, and whoever installed it did the minmum. Patio has since been laid on top of it. The existing run is 75 - 100 yards, a new run would also need trenching even if I go around the patio.

The distance from "South pond to North pond" is 30, or maybe 40, yards extra.

I haven't priced the cable, but the rest of the disruption! is the part that will cost the most, plus Mr Sparky to install both ends, whereas the current setup has a nice waterproof junction box by the South pond, and even I could safely wire a new pump into it :thumb:

But sounds like its arse-about-face and I should put the pump and the North lower end and push the water uphill.

 

If you want the best circulation within the pond then the pump suction or inlet should be sited at the lowest point in the pond. The discharge or outlet from the pump should feed into the highest point of the pond. Mine goes to a waterfall for example.

This will help to oxygenate the water and avoid stagnent areas developing.

The only caveat is that the pump needs to be powerfull enough to move the water from the lowest to the highest point in the pond with the required flow rate. This is termed the max head or total head capacity of the pump.

I hope thats clear.....

 

Musa Monkey, sorry, If only Kirsten's problem was that easy to solve.
Read his post again, slowly. It’s not how to best locate a pump that is being questioned.

 

Seems very clear to me, here is a direct quote which refers to pump location;

So my question is:

Can I put a "pull" pump in South pond, instead of the current "push"
pump in North pond - then I won't have to do any extra wiring.

i.e. a specific pump type in one pond rather than the other. What i was trying to explain was the benefits of proper location regardless of pump type and that the chosen pump capacity needed to be adequate.

The easy answer to the question is YES, providing the pump has adequate suction and head capacity.